Indane-amines as pd-l1 antagonists

ABSTRACT

Compounds are provided that are useful as immunomodulators. The compounds have the Formula (I) 
     
       
         
         
             
             
         
       
     
     including stereoisomers and pharmaceutically acceptable salts thereof, wherein R 1 , R 2a , R 2b , R 2c , R 3 , R 4 , R 5 , R 6a , R 6b , m and n are as defined herein. Methods associated with preparation and use of such compounds, as well as pharmaceutical compositions comprising such compounds, are also disclosed.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No. 16/742,104 filed Jan. 14, 2021, which is a continuation of Ser. No. 16/281,448 filed Feb. 21, 2019 (now U.S. Pat. No. 10,568,874), which application claims priority benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 62/633,973 filed Feb. 22, 2018, each of which is incorporated herein by reference in its entirety for all purposes.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

NOT APPLICABLE

REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK

NOT APPLICABLE

BACKGROUND OF THE DISCLOSURE

Programmed cell death protein-1 (PD-1) is a member of the CD28 superfamily that delivers negative signals upon interaction with its two ligands, PD-L1 or PD-L2. PD-1 and its ligands are broadly expressed and exert a wide range of immunoregulatory roles in T cell activation and tolerance. PD-1 and its ligands are involved in attenuating infectious immunity and tumor immunity, and facilitating chronic infection and tumor progression.

Modulation of the PD-1 pathway has therapeutic potential in various human diseases (Hyun-Tak Jin et al., Curr Top Microbiol Immunol. (2011); 350:17-37). Blockade of the PD-1 pathway has become an attractive target in cancer therapy. Therapeutic antibodies that block the programmed cell death protein-1 (PD-1) immune checkpoint pathway prevent T-cell down regulation and promote immune responses against cancer. Several PD-1 pathway inhibitors have shown robust activity in various phases of clinical trials (R D Harvey, Clinical Pharmacology and Therapeutics (2014); 96(2), 214-223).

Agents that block the interaction of PD-L1 with either PD-1 or CD80 are desired. Some antibodies have been developed and commercialized. A few patent applications disclosing non-peptidic small molecules have been published (WO 2015/160641, WO 2015/034820, and WO 2017/066227 and WO2018/009505 from BMS; WO 2015/033299 and WO 2015/033301 from Aurigene; WO 2017/070089, US 2017/0145025, WO 2017/106634, US2017/0174679, WO2017/192961, WO2017/222976, WO2017/205464, WO2017/112730, WO2017/041899 and WO2018/013789 from Incyte, WO2018/006795 from Maxinovel and WO2018/005374 from us, ChemoCentryx). However there is still a need for alternative compounds such as small molecules as inhibitors of PD-L1, and which may have advantageous characteristics in term of oral administration, stability, bioavailability, therapeutic index, and toxicity.

BRIEF SUMMARY OF THE DISCLOSURE

In one aspect, provided herein are compounds having formula (I):

or a pharmaceutically acceptable salt thereof, or a prodrug or bioisostere thereof; wherein: R¹, R^(2a), R^(2b), R^(2c), R³, R⁴, R⁵, R^(6a), R^(6b), m, and n, are as defined herein.

In addition to the compounds provided herein, the present disclosure further provides pharmaceutical compositions containing one or more of these compounds, as well as methods associated with preparation and use of such compounds. In some embodiments, the compounds are used in therapeutic methods to treat diseases associated with the PD-1/PD-L1 pathway.

BRIEF DESCRIPTION OF THE DRAWINGS

NOT APPLICABLE

DETAILED DESCRIPTION OF THE DISCLOSURE Abbreviation and Definitions

The terms “a,” “an,” or “the” as used herein not only include aspects with one member, but also include aspects with more than one member. For instance, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a cell” includes a plurality of such cells and reference to “the agent” includes reference to one or more agents known to those skilled in the art, and so forth.

The terms “about” and “approximately” shall generally mean an acceptable degree of error for the quantity measured given the nature or precision of the measurements. Typical, exemplary degrees of error are within 20 percent (%), preferably within 10%, and more preferably within 5% of a given value or range of values. Alternatively, and particularly in biological systems, the terms “about” and “approximately” may mean values that are within an order of magnitude, preferably within 5-fold and more preferably within 2-fold of a given value. Numerical quantities given herein are approximate unless stated otherwise, meaning that the term “about” or “approximately” can be inferred when not expressly stated.

The term “alkyl”, by itself or as part of another substituent, means, unless otherwise stated, a straight or branched chain hydrocarbon group, having the number of carbon atoms designated (i.e. C₁₋₈ means one to eight carbons). Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, sec-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and the like. The term “alkenyl” refers to an unsaturated alkyl group having one or more double bonds. Similarly, the term “alkynyl” refers to an unsaturated alkyl group having one or more triple bonds. Examples of alkenyl groups include vinyl, 2-propenyl, crotyl, 2-isopentenyl, 2-(butadienyl), 2,4-pentadienyl and 3-(1,4-pentadienyl). Examples of alkynyl groups include ethynyl, 1- and 3-propynyl, 3-butynyl, and the higher homologs and isomers. The term “cycloalkyl” refers to hydrocarbon rings having the indicated number of ring atoms (e.g., C₃₋₆cycloalkyl) and being fully saturated or having no more than one double bond between ring vertices. “Cycloalkyl” is also meant to refer to bicyclic and polycyclic hydrocarbon rings such as, for example, bicyclo[2.2.1]heptane, bicyclo[2.2.2]octane, etc. The bicyclic or polycyclic rings may be fused, bridged, spiro or a combination thereof. The term “heterocycloalkyl” or “heterocyclyl” refers to a cycloalkyl group that contain from one to five heteroatoms selected from N, O, and S, wherein the nitrogen and sulfur atoms are optionally oxidized, and the nitrogen atom(s) are optionally quaternized. The heterocycloalkyl may be a monocyclic, a bicyclic or a polycyclic ring system. The bicyclic or polycyclic rings may be fused, bridged, spiro or a combination thereof. It is understood that the recitation for C₄₋₁₂ heterocyclyl, refers to a group having from 4 to 12 ring members where at least one of the ring members is a heteroatom. Non limiting examples of heterocycloalkyl groups include pyrrolidine, imidazolidine, pyrazolidine, butyrolactam, valerolactam, imidazolidinone, tetrazolone, hydantoin, dioxolane, phthalimide, piperidine, 1,4-dioxane, morpholine, thiomorpholine, thiomorpholine-S-oxide, thiomorpholine-S,S-oxide, piperazine, pyran, pyridone, 3-pyrroline, thiopyran, pyrone, tetrahydrofuran, tetrahydrothiophene, quinuclidine, and the like. A heterocycloalkyl group can be attached to the remainder of the molecule through a ring carbon or a heteroatom.

The term “alkylene” by itself or as part of another substituent means a divalent group derived from an alkane, as exemplified by —CH₂CH₂CH₂CH₂—. Typically, an alkyl (or alkylene) group will have from 1 to 12 carbon atoms, with those groups having 8 or fewer carbon atoms being preferred in the present disclosure. Similarly, “alkenylene” and “alkynylene” refer to the unsaturated forms of “alkylene” having double or triple bonds, respectively.

The term “heteroalkyl,” by itself or in combination with another term, means, unless otherwise stated, a stable straight or branched chain, or cyclic hydrocarbon group, or combinations thereof, consisting of the stated number of carbon atoms and from one to three heteroatoms selected from the group consisting of O, N, Si and S, and wherein the nitrogen and sulfur atoms may optionally be oxidized and the nitrogen heteroatom may optionally be quaternized. The heteroatom(s) O, N and S may be placed at any interior position of the heteroalkyl group. The heteroatom Si may be placed at any position of the heteroalkyl group, including the position at which the alkyl group is attached to the remainder of the molecule. Examples include —CH₂—CH₂—O—CH₃, —CH₂—CH₂—NH—CH₃, —CH₂—CH₂—N(CH₃)—CH₃, —CH₂—S—CH₂—CH₃, —CH₂—CH₂, —S(O)—CH₃, —CH₂—CH₂—S(O)₂—CH₃, —CH═CHO—CH₃, —Si(CH₃)₃, —CH₂—CH═N—OCH₃, and —CH═CH—N(CH₃)—CH₃. Up to two heteroatoms may be consecutive, such as, for example, —CH₂—NH—OCH₃ and —CH₂—O—Si(CH₃)₃. Similarly, the terms “heteroalkenyl” and “heteroalkynyl” by itself or in combination with another term, means, unless otherwise stated, an alkenyl group or alkynyl group, respectively, that contains the stated number of carbons and having from one to three heteroatoms selected from the group consisting of O, N, Si and S, and wherein the nitrogen and sulfur atoms may optionally be oxidized and the nitrogen heteroatom may optionally be quaternized. The heteroatom(s) O, N and S may be placed at any interior position of the heteroalkyl group.

The term “heteroalkylene” by itself or as part of another substituent means a divalent group, saturated or unsaturated or polyunsaturated, derived from heteroalkyl, as exemplified by —CH₂—CH₂—S—CH₂CH₂— and —CH₂—S—CH₂—CH₂—NH—CH₂—, —O—CH₂—CH═CH—, —CH₂—CH═C(H)CH₂—O—CH₂— and —S—CH₂—C═C—. For heteroalkylene groups, heteroatoms can also occupy either or both of the chain termini (e.g., alkyleneoxy, alkylenedioxy, alkyleneamino, alkylenediamino, and the like).

The terms “alkoxy,” “alkylamino” and “alkylthio” (or thioalkoxy) are used in their conventional sense, and refer to those alkyl groups attached to the remainder of the molecule via an oxygen atom, an amino group, or a sulfur atom, respectively. Additionally, for dialkylamino groups, the alkyl portions can be the same or different and can also be combined to form a 3-7 membered ring with the nitrogen atom to which each is attached. Accordingly, a group represented as —NR^(a)R^(b) is meant to include piperidinyl, pyrrolidinyl, morpholinyl, azetidinyl and the like.

The terms “halo” or “halogen,” by themselves or as part of another substituent, mean, unless otherwise stated, a fluorine, chlorine, bromine, or iodine atom. Additionally, terms such as “haloalkyl,” are meant to include monohaloalkyl and polyhaloalkyl. For example, the term “C₁₋₄ haloalkyl” is mean to include trifluoromethyl, 2,2,2-trifluoroethyl, 4-chlorobutyl, 3-bromopropyl, and the like.

The term “hydroxyalkyl” or “alkyl-OH” refers to an alkyl group, as defined above, where at least one (and up to three) of the hydrogen atoms is replaced with a hydroxy group. As for the alkyl group, hydroxyalkyl groups can have any suitable number of carbon atoms, such as C₁₋₆. Exemplary hydroxyalkyl groups include, but are not limited to, hydroxymethyl, hydroxyethyl (where the hydroxy is in the 1- or 2-position), hydroxypropyl (where the hydroxy is in the 1-, 2- or 3-position), and 2,3-dihydroxypropyl.

The term “C₁₋₃ alkyl-guanidinyl” refers to a C₁₋₃ alkyl group, as defined above, where at least one of the hydrogen atoms is replaced with a guanidinyl group (—NHC(NH)NH₂).

The term “aryl” means, unless otherwise stated, a polyunsaturated, typically aromatic, hydrocarbon group which can be a single ring or multiple rings (up to three rings) which are fused together or linked covalently. The term “heteroaryl” refers to aryl groups (or rings) that contain from one to five heteroatoms selected from N, O, and S, wherein the nitrogen and sulfur atoms are optionally oxidized, and the nitrogen atom(s) are optionally quaternized. A heteroaryl group can be attached to the remainder of the molecule through a heteroatom. It is understood that the recitation for C₅₋₁₀ heteroaryl, refers to a heteroaryl moiety having from 5 to 10 ring members where at least one of the ring members is a heteroatom. Non-limiting examples of aryl groups include phenyl, naphthyl and biphenyl, while non-limiting examples of heteroaryl groups include pyridyl, pyridazinyl, pyrazinyl, pyrimindinyl, triazinyl, quinolinyl, quinoxalinyl, quinazolinyl, cinnolinyl, phthalaziniyl, benzotriazinyl, purinyl, benzimidazolyl, benzopyrazolyl, benzotriazolyl, benzisoxazolyl, isobenzofuryl, isoindolyl, indolizinyl, benzotriazinyl, thienopyridinyl, thienopyrimidinyl, pyrazolopyrimidinyl, imidazopyridines, benzothiaxolyl, benzofuranyl, benzothienyl, indolyl, quinolyl, isoquinolyl, isothiazolyl, pyrazolyl, indazolyl, pteridinyl, imidazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, thiadiazolyl, pyrrolyl, thiazolyl, furyl, thienyl and the like. Substituents for each of the above noted aryl and heteroaryl ring systems are selected from the group of acceptable substituents described below.

The term “carbocyclic ring,” “carbocyclic” or “carbocyclyl” refers to cyclic moieties with only carbon atoms as ring vertices. Carbocyclic ring moieties are saturated or unsaturated and can be aromatic. Generally, carbocyclic moieties have from 3 to 10 ring members. Carbocylic moieties with multiple ring structure (e.g. bicyclic) can include a cycloalkyl ring fused to an aromatic ring (e.g. 1,2,3,4-tetrahydronaphthalene). Thus, carbocyclic rings include cyclopentyl, cyclohexenyl, naphthyl, and 1,2,3,4-tetrahydronaphthyl. The term “heterocyclic ring” refers to both “heterocycloalkyl” and “heteroaryl” moieties. Thus, heterocyclic rings are saturated or unsaturated and can be aromatic. Generally, heterocyclic rings are 4 to 10 ring members and include piperidinyl, tetrazinyl, pyrazolyl and indolyl.

When any of the above terms (e.g., “alkyl,” “aryl” and “heteroaryl”) are referred to as ‘substituted’ without further notation on the substituents, the substituted forms of the indicated group will be as provided below.

Substituents for the alkyl groups (including those groups often referred to as alkylene, alkenyl, alkynyl and cycloalkyl) can be a variety of groups selected from: -halogen, —OR′, —NR′R″, —SR′, —SiR′R″R″′, —OC(O)R′, —C(O)R′, —CO₂R′, —CONR′R″, —OC(O)NR′R″, —NR″C(O)R′, —NR′—C(O)NR″R″′, —NR″C(O)₂R′, —NH—C(NH₂)═NH, —NR′C(NH₂)═NH, —NH—C(NH₂)═NR′, —S(O)R′, —S(O)₂R′, —S(O)₂NR′R″, —NR′S(O)₂R″, —CN and —NO₂ in a number ranging from zero to (2 m′+1), where m′ is the total number of carbon atoms in such group. R′, R″ and R″′ each independently refer to hydrogen, unsubstituted C₁₋₈ alkyl, unsubstituted heteroalkyl, unsubstituted aryl, aryl substituted with 1-3 halogens, unsubstituted C₁₋₈ alkyl, C₁₋₈ alkoxy or C₁₋₈ thioalkoxy groups, or unsubstituted aryl-C₁₋₄ alkyl groups. When R′ and R″ are attached to the same nitrogen atom, they can be combined with the nitrogen atom to form a 3-, 4-, 5-, 6-, or 7-membered ring. For example, —NR′R″ is meant to include 1-pyrrolidinyl and 4-morpholinyl. The term “acyl” as used by itself or as part of another group refers to an alkyl group wherein two substitutents on the carbon that is closest to the point of attachment for the group is replaced with the substitutent ═O (e.g., —C(O)CH₃, —C(O)CH₂CH₂OR′ and the like).

Similarly, substituents for the aryl and heteroaryl groups are varied and are generally selected from: -halogen, —OR′, —OC(O)R′, —NR′R″, —SR′, —R′, —CN, —NO₂, —CO₂R′, —CONR′R″, —C(O)R′, —OC(O)NR′R″, —NR″C(O)R′, —NR″C(O)₂R′, —NR′—C(O)NR″R″′, —NH—C(NH₂)═NH, —NR′C(NH₂)═NH, —NH—C(NH₂)═NR′, —S(O)R′, —S(O)₂R′, —S(O)₂NR′R″, —NR′S(O)₂R″, —N₃, perfluoro(C₁-C₄)alkoxy, and perfluoro(C₁-C₄)alkyl, in a number ranging from zero to the total number of open valences on the aromatic ring system; and where R′, R″ and R″′ are independently selected from hydrogen, C₁₋₈ alkyl, C₃₋₆ cycloalkyl, C₂₋₈ alkenyl, C₂₋₈ alkynyl, unsubstituted aryl and heteroaryl, (unsubstituted aryl)-C₁₋₄ alkyl, and unsubstituted aryloxy-C₁₋₄ alkyl. Other suitable substituents include each of the above aryl substituents attached to a ring atom by an alkylene tether of from 1-4 carbon atoms.

Two of the substituents on adjacent atoms of the aryl or heteroaryl ring may optionally be replaced with a substituent of the formula -T-C(O)—(CH₂)_(q)-U-, wherein T and U are independently —NH—, —O—, —CH₂— or a single bond, and q is an integer of from 0 to 2. Alternatively, two of the substituents on adjacent atoms of the aryl or heteroaryl ring may optionally be replaced with a substituent of the formula -A-(CH₂)_(r)-B-, wherein A and B are independently —CH₂—, —O—, —NH—, —S—, —S(O)—, —S(O)₂—, —S(O)₂NR′— or a single bond, and r is an integer of from 1 to 3. One of the single bonds of the new ring so formed may optionally be replaced with a double bond. Alternatively, two of the substituents on adjacent atoms of the aryl or heteroaryl ring may optionally be replaced with a substituent of the formula —(CH₂)_(s)—X—(CH₂)_(t)—, where s and t are independently integers of from 0 to 3, and X is —O—, —NR′—, —S—, —S(O)—, —S(O)₂—, or —S(O)₂NR′—. The substituent R′ in —NR′— and —S(O)₂NR′— is selected from hydrogen or unsubstituted C₁₋₆ alkyl.

As used herein, the term “heteroatom” is meant to include oxygen (O), nitrogen (N), sulfur (S) and silicon (Si).

The disclosure herein further relates to prodrugs and bioisosteres thereof. Suitable bioisosteres, for example, will include carboxylate replacements (phosphonic acids, phosphinic acids, sulfonic acids, sulfinic acids, and acidic heterocyclic groups such as tetrazoles). Suitable prodrugs will include those conventional groups known to hydrolyze and/or oxidize under physiological conditions to provide a compound of Formula I.

The terms “patient” and “subject” include primates (especially humans), domesticated companion animals (such as dogs, cats, horses, and the like) and livestock (such as cattle, pigs, sheep, and the like).

As used herein, the term “treating” or “treatment” encompasses both disease-modifying treatment and symptomatic treatment, either of which may be prophylactic (i.e., before the onset of symptoms, in order to prevent, delay or reduce the severity of symptoms) or therapeutic (i.e., after the onset of symptoms, in order to reduce the severity and/or duration of symptoms).

The term “pharmaceutically acceptable salts” is meant to include salts of the active compounds which are prepared with relatively nontoxic acids or bases, depending on the particular substituents found on the compounds described herein. When compounds of the present disclosure contain relatively acidic functionalities, base addition salts can be obtained by contacting the neutral form of such compounds with a sufficient amount of the desired base, either neat or in a suitable inert solvent. Examples of salts derived from pharmaceutically-acceptable inorganic bases include aluminum, ammonium, calcium, copper, ferric, ferrous, lithium, magnesium, manganic, manganous, potassium, sodium, zinc and the like. Salts derived from pharmaceutically-acceptable organic bases include salts of primary, secondary and tertiary amines, including substituted amines, cyclic amines, naturally-occuring amines and the like, such as arginine, betaine, caffeine, choline, N,N′-dibenzylethylenediamine, diethylamine, 2-diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine, ethylenediamine, N-ethylmorpholine, N-ethylpiperidine, glucamine, glucosamine, histidine, hydrabamine, isopropylamine, lysine, methylglucamine, morpholine, piperazine, piperadine, polyamine resins, procaine, purines, theobromine, triethylamine, trimethylamine, tripropylamine, tromethamine and the like. When compounds of the present disclosure contain relatively basic functionalities, acid addition salts can be obtained by contacting the neutral form of such compounds with a sufficient amount of the desired acid, either neat or in a suitable inert solvent. Examples of pharmaceutically acceptable acid addition salts include those derived from inorganic acids like hydrochloric, hydrobromic, nitric, carbonic, monohydrogencarbonic, phosphoric, monohydrogenphosphoric, dihydrogenphosphoric, sulfuric, monohydrogensulfuric, hydriodic, or phosphorous acids and the like, as well as the salts derived from relatively nontoxic organic acids like acetic, propionic, isobutyric, malonic, benzoic, succinic, suberic, fumaric, mandelic, phthalic, benzenesulfonic, p-tolylsulfonic, citric, tartaric, methanesulfonic, and the like. Also included are salts of amino acids such as arginate and the like, and salts of organic acids like glucuronic or galactunoric acids and the like (see, for example, Berge, S. M., et al, “Pharmaceutical Salts”, Journal of Pharmaceutical Science, 1977, 66, 1-19). Certain specific compounds of the present disclosure contain both basic and acidic functionalities that allow the compounds to be converted into either base or acid addition salts.

The neutral forms of the compounds may be regenerated by contacting the salt with a base or acid and isolating the parent compound in the conventional manner. The parent form of the compound differs from the various salt forms in certain physical properties, such as solubility in polar solvents, but otherwise the salts are equivalent to the parent form of the compound for the purposes of the present disclosure.

Certain compounds of the present disclosure can exist in unsolvated forms as well as solvated forms, including hydrated forms. In general, the solvated forms are equivalent to unsolvated forms and are intended to be encompassed within the scope of the present disclosure. Certain compounds of the present disclosure may exist in multiple crystalline or amorphous forms. In general, all physical forms are equivalent for the uses contemplated by the present disclosure and are intended to be within the scope of the present disclosure.

Certain compounds of the present invention possess asymmetric carbon atoms (optical centers) or double bonds; the racemates, diastereomers, geometric isomers, regioisomers and individual isomers (e.g., separate enantiomers) are all intended to be encompassed within the scope of the present invention. When a stereochemical depiction is shown, it is meant to refer to the compound in which one of the isomers is present and substantially free of the other isomer. ‘Substantially free of’ another isomer indicates at least an 80/20 ratio of the two isomers, more preferably 90/10, or 95/5 or more. In some embodiments, one of the isomers will be present in an amount of at least 99%.

The compounds of the present disclosure may also contain unnatural proportions of atomic isotopes at one or more of the atoms that constitute such compounds. For example, the compounds may be radiolabeled with radioactive isotopes, such as for example tritium (3H), iodine-125 (¹²⁵I) or carbon-14 (¹⁴C). All isotopic variations of the compounds of the present disclosure, whether radioactive or not, are intended to be encompassed within the scope of the present disclosure. For example, the compounds may be prepared such that any number of hydrogen atoms are replaced with a deuterium (²H) isotope. The compounds of the present disclosure may also contain unnatural proportions of atomic isotopes at one or more of the atoms that constitute such compounds. Unnatural proportions of an isotope may be defined as ranging from the amount found in nature to an amount consisting of 100% of the atom in question. For example, the compounds may incorporate radioactive isotopes, such as for example tritium (³H), iodine-125 (¹²⁵I) or carbon-14 (¹⁴C), or non-radioactive isotopes, such as deuterium (²H) or carbon-13 (¹³C). Such isotopic variations can provide additional utilities to those described elsewhere within this application. For instance, isotopic variants of the compounds of the disclosure may find additional utility, including but not limited to, as diagnostic and/or imaging reagents, or as cytotoxic/radiotoxic therapeutic agents. Additionally, isotopic variants of the compounds of the disclosure can have altered pharmacokinetic and pharmacodynamic characteristics which can contribute to enhanced safety, tolerability or efficacy during treatment. All isotopic variations of the compounds of the present disclosure, whether radioactive or not, are intended to be encompassed within the scope of the present disclosure.

Compounds

In one aspect, the present disclosure provides compounds having formula (I):

or a pharmaceutically acceptable salt thereof, or a prodrug or bioisostere thereof,

wherein: R¹ is selected from Formula (IIa) or Formula (IIb):

-   each of substitutents R^(1a), R^(1b), R^(1c), R^(1d) and R^(1e) is     independently selected from the group consisting of H, halogen, —CN,     —R^(c), —CO₂R^(a), —CONR^(a)R^(b), —C(O)R^(a), —OC(O)NR^(a)R^(b),     —NR^(b)C(O)R^(a), —NR^(b)C(O)₂R^(c), —NR^(a)—C(O)NR^(a)R^(b),     —NR^(a)R^(b), —OR^(a), —O—X¹—OR^(a), —O—X¹—CO₂R^(a),     —O—X¹—CONR^(a)R^(b), —X¹—OR^(a), —X¹—NR^(a)R^(b), —X₁—CO₂R^(a),     —X¹—CONR^(a)R^(b), —SF₅, and —S(O)₂NR^(a)R^(b), wherein each X¹ is a     C₁₋₄ alkylene; each R^(a) and R^(b) is independently selected from     hydrogen, C₁₋₈ alkyl, and C₁₋₈ haloalkyl, or when attached to the     same nitrogen atom can be combined with the nitrogen atom to form a     five or six-membered ring having from 0 to 2 additional heteroatoms     as ring members selected from N, O or S, wherein the five or     six-membered ring is optionally substituted with oxo; each R^(c) is     independently selected from the group consisting of C₁₋₈ alkyl, C₂₋₈     alkenyl, C₂₋₈ alkynyl and C₁₋₈ haloalkyl; and optionally when two     substituents are on adjacent carbon atoms of the benzene ring, they     may combine to form a fused five, six or seven-membered carbocyclic     or heterocyclic ring optionally substituted with from 1 to 3     substituents independently selected from halo, oxo, C₁₋₈ haloalkyl     and C₁₋₈ alkyl;     L is a linking group selected from the group consisting of:

-   wherein each of the subscripts q is independently 1, 2, 3 or 4, and     L is optionally further substituted with one or two members selected     from the group consisting of halogen, hydroxy, C₁₋₃ alkyl, —O—C₁₋₃     alkyl, C₁₋₃ hydroxyalkyl, C₁₋₃ haloalkyl and —CO₂H; -   Z is selected from the group consisting of azetidinyl, pyrollidinyl,     piperidinyl, morpholinyl, pyridyl, pyrimidinyl, guanidinyl,     quinuclidine, and 8-azabicyclo[3.2.1]octane, each of which is     optionally substituted with from 1 to 3 groups independently     selected from halogen, hydroxy, C₁₋₃ alkyl, —NH₂, —NHC₁₋₃alkyl,     —N(C₁₋₃alkyl)₂, —O—C₁₋₃ alkyl, C₁₋₃ hydroxyalkyl, C₁₋₃ haloalkyl and     —CO₂H;     or -   Z is selected from the group consisting of —CO₂R^(z1) and     —NR^(z1)R^(z2); wherein R^(z1) is selected from the group consisting     of H, C₁₋₈ alkyl, C₁₋₈ haloalkyl and C₁₋₈ hydroxyalkyl; and R^(z2)     is selected from —C₁₋₈ alkyl, C₁₋₈ haloalkyl, C₁₋₈ alkyl-COOH, C₁₋₈     alkyl-OH, C₁₋₈ alkyl-CONH₂, C₁₋₈ alkyl-SO₂NH₂, C₁₋₈ alkyl-PO₃H₂,     C₁₋₈ alkyl-C(O)NHOH, —C(O)—C₁₋₈alkyl-OH, —C(O)—C₁₋₈alkyl-COOH, C₃₋₁₀     cycloalkyl, —C₃₋₁₀ cycloalkyl-COOH, —C₃₋₁₀ cycloalkyl-OH, C₄₋₈     heterocyclyl, —C₄₋₈ heterocyclyl-COOH, —C₄₋₈ heterocyclyl-OH,     —C₁₋₈alkyl-C₄₋₈ heterocyclyl, —C₁₋₈ alkyl-C₃₋₁₀ cycloalkyl, C₅₋₁₀     heteroaryl and —C₁₋₈alkyl-C₅₋₁₀ heteroaryl; -   each R^(2a), R^(2b) and R^(2c) is independently selected from the     group consisting of H, halogen, —CN, —R^(d), —CO₂R^(e),     —CONR^(e)R^(f), —OC(O)NR^(e)R^(f), —NR^(f)C(O)R^(e),     —NR^(f)C(O)₂R^(d), —NR^(e)—C(O)NR^(e)R^(f), —NR^(e)R^(f), —OR^(e),     —X²—OR^(e), —X²—NR^(e)R^(f), —X²—CO₂R^(e), —SF₅, and     —S(O)₂NR^(e)R^(f), wherein each X² is a C₁₋₄ alkylene; each R^(e)     and R^(f) is independently selected from hydrogen, C₁₋₈ alkyl, and     C₁₋₈ haloalkyl, or when attached to the same nitrogen atom can be     combined with the nitrogen atom to form a five or six-membered ring     having from 0 to 2 additional heteroatoms as ring members selected     from N, O and S, and optionally substituted with oxo; each R^(d) is     independently selected from the group consisting of C₁₋₈ alkyl, C₂₋₈     alkenyl, and C₁₋₈ haloalkyl; -   R³ is selected from the group consisting of —NR^(g)R^(h) and C₄₋₁₂     heterocyclyl, wherein the C₄₋₁₂ heterocyclyl is optionally     substituted with 1 to 6 R^(3a); -   each R^(3a) is independently selected from the group consisting of     halogen, —CN, —R^(i), —CO₂R^(j), —CONR^(j)R^(k), —CONHC₁₋₆ alkyl-OH,     —C(O)R^(j), —OC(O)NR^(j)R^(k), —NR^(j)C(O)R^(k), —NR^(j)C(O)₂R^(k),     —CONHOH, —PO₃H₂, —NR^(j)—X³—C(O)₂R^(k), —NR^(j)C(O)NR^(j)R^(k),     —NR^(j)R^(k), —OR^(j), —S(O)₂NR^(j)R^(k), —O—X³—OR^(j),     —O—X³—NR^(j)R^(k), —O—X³—CO₂R^(j), —O—X³—CONR^(j)R^(k), —X³—OR^(j),     —X³—NR^(j)R^(k), —X³—CO₂R^(j), —X³—CONR^(j)R^(k), —X³—CONHSO₂R^(j)     and SF₅; wherein X³ is C₁₋₆ alkylene and is optionally further     substituted with OH, SO₂NH₂, CONH₂, C(O)NHOH, PO₃H₂, COO—C₁₋₈alkyl     or CO₂H, wherein each R^(j) and R^(k) is independently selected from     hydrogen, C₁₋₈ alkyl optionally substituted with 1 to 2 substituents     selected from OH, SO₂NH₂, CONH₂, C(O)NHOH, PO₃H₂, COO—C₁₋₈alkyl or     CO₂H, and C₁₋₈ haloalkyl optionally substituted with 1 to 2     substituents selected from OH, SO₂NH₂, CONH₂, C(O)NHOH, PO₃H₂,     COO—C₁₋₈alkyl or CO₂H, or when attached to the same nitrogen atom     R^(j) and R^(k) can be combined with the nitrogen atom to form a     five or six-membered ring having from 0 to 2 additional heteroatoms     as ring members selected from N, O or S, and optionally substituted     with oxo; each R^(i) is independently selected from the group     consisting of —OH, C₁₋₈ alkyl, C₂₋₈ alkenyl, and C₁₋₈ haloalkyl each     of which may be optionally substituted with OH, SO₂NH₂, CONH₂,     C(O)NHOH, PO₃H₂, COO—C₁₋₈alkyl or CO₂H; -   R^(g) is selected from the group consisting of H, C₁₋₈ haloalkyl and     C₁₋₈ alkyl; -   R^(h) is selected from —C₁₋₈ alkyl, C₁₋₈ haloalkyl, C₁₋₈     hydroxyalkyl, C₁₋₈alkyl-CO₂R^(j), C₁₋₈alkyl-CONR^(j)R^(k), and     C₁₋₈alkyl-CONHSO₂R^(j), C₁₋₈ alkyl-SO₂NR^(j)R^(k), C₁₋₈ alkyl-PO₃H₂,     C₁₋₈ alkyl-C(O)NHOH, C₁₋₈ alkyl-NR^(h1)R^(h2), —C(O)R^(j), C₃₋₁₀     cycloalkyl, —C₃₋₁₀ cycloalkyl-COOR^(j), —C₃₋₁₀ cycloalkyl-OR^(j),     C₄₋₈ heterocyclyl, —C₄₋₈ heterocyclyl-COOR^(j), —C₄₋₈     heterocyclyl-OR^(j), —C₁₋₈ alkyl-C₄₋₈ heterocyclyl, —C(═O)OC₁₋₈     alkyl-C₄₋₈ heterocyclyl, —C₁₋₈ alkyl-C₃₋₁₀ cycloalkyl, C₅₋₁₀     heteroaryl, —C₁₋₈alkyl-C₅₋₁₀ heteroaryl, —C₁₋₈ alkyl-C₆₋₁₀ aryl,     —C₁₋₈ alkyl-(C═O)—C₆₋₁₀ aryl, —CO₂—C₁₋₈ alkyl-O₂C—C₁₋₈ alkyl, —C₁₋₈     alkyl-NH(C═O)—C₂₋₈ alkenyl, —C₁₋₈ alkyl-NH(C═O)—C₁₋₈ alkyl, —C₁₋₈     alkyl-NH(C═O)—C₂₋₈ alkynyl, —C₁₋₈ alkyl-(C═O)—NH—C₁₋₈     alkyl-COOR^(j), and —C₁₋₈ alkyl-(C═O)—NH—C₁₋₈ alkyl-OR^(j)     optionally substituted with CO₂H; or     -   R^(h) combined with the N to which it is attached is a mono-,         di- or tri-peptide comprising 1-3 natural amino acids and 0-2         non-natural amino acids, wherein     -   the non-natural aminoacids have an alpha carbon substituent         selected from the group consisting of C₂₋₄ hydroxyalkyl, C₁₋₃         alkyl-guanidinyl, and C₁₋₄ alkyl-heteroaryl,     -   the alpha carbon of each natural or non-natural amino acids are         optionally further substituted with a methyl group, and     -   the terminal moiety of the mono-, di-, or tri-peptide is         selected from the group consisting of C(O)OH, C(O)O—C₁₋₆ alkyl,         and PO₃H₂, wherein     -   R^(h1) and R^(h2) are each independently selected from the group         consisting of H, C₁₋₆ alkyl, and C₁₋₄ hydroxyalkyl;     -   the C₁₋₈ alkyl portions of R^(h) are optionally further         substituted with from 1 to 3 substituents independently selected         from OH, COOH, SO₂NH₂, CONH₂, C(O)NHOH, COO—C₁₋₈ alkyl, PO₃H₂         and C₅₋₆ heteroaryl optionally substituted with 1 to 2 C₁₋₃         alkyl substituents,     -   the C₅₋₁₀ heteroaryl and the C₆₋₁₀ aryl portions of R^(h) are         optionally substituted with 1 to 3 substituents independently         selected from OH, B(OH)₂, COOH, SO₂NH₂, CONH₂, C(O)NHOH, PO₃H₂,         COO—C₁₋₈alkyl, C₁₋₄alkyl, C₁₋₄alkyl-OH, C₁₋₄alkyl-SO₂NH₂,         C₁₋₄alkyl CONH₂, C₁₋₄alkyl-C(O)NHOH, C₁₋₄alkyl-PO₃H₂,         C₁₋₄alkyl-COOH and phenyl, and     -   the C₄₋₈ heterocyclyl and C₃₋₁₀ cycloalkyl portions of R^(h) are         optionally substituted with 1 to 4 R^(w) substituents; -   each R^(w) substituent is independently selected from C₁₋₄ alkyl,     C₁₋₄ alkyl-OH, C₁₋₄ alkyl-COOH, C₁₋₄ alkyl-SO₂NH₂, C₁₋₄ alkyl CONH₂,     C₁₋₄ alkyl-C(O)NHOH, C₁₋₄ alkyl-PO₃H, OH, COO—C₁₋₈ alkyl, COOH,     SO₂NH₂, CONH₂, C(O)NHOH, PO₃H₂ and oxo; -   R⁴ is selected from the group consisting of O—C₁₋₈ alkyl, O—C₁₋₈     haloalkyl, C₆₋₁₀ aryl, C₅₋₁₀ heteroaryl, —O—C₁₋₄ alkyl-C₄₋₇     heterocycloalkyl, —O—C₁₋₄ alkyl-C₆₋₁₀aryl and —O—C₁₋₄ alkyl-C₅₋₁₀     heteroaryl, each of which is optionally substituted with 1 to 5     R^(4a); -   each R^(4a) is independently selected from the group consisting of     halogen, —CN, —R^(m), —CO₂R^(n), —CONR^(n)R^(p), —C(O)R^(n),     —OC(O)NR^(n)R^(p), —NR^(n)C(O)R^(P), —NR^(n)C(O)₂R^(m),     —NR^(n)—C(O)NR^(n)R^(p), —NR^(n)R^(p), —OR^(n), —O—X⁴—OR^(n),     —O—X⁴—NR^(n)R^(p), —O—X⁴—CO₂R^(n), —O—X⁴—CONR^(n)R^(p), —X⁴—OR^(n),     —X⁴—NR^(n)R^(p), —X⁴—CO₂R^(n), —X⁴—CONR^(n)R^(p), —SF₅,     —S(O)₂R^(n)R^(p), —S(O)₂NR^(n)R^(p), C₃₋₇ cycloalkyl and C₄₋₇     heterocycloalkyl, wherein the cycloalkyl and heterocycloalkyl rings     are optionally substituted with 1 to 5 R^(t), wherein each R^(t) is     independently selected from the group consisting of C₁₋₈ alkyl,     C₁₋₈-haloalkyl, —CO₂R^(n), —CONR^(n)R^(p), —C(O)R^(n),     —OC(O)NR^(n)R^(p), —NR^(n)C(O)R^(p), —NR^(n)C(O)₂R^(m),     —NR^(n)—C(O)NR^(n)R^(p), —NR^(n)R^(p), —OR^(n), —O—X⁴—OR^(n),     —O—X⁴—NR^(n)R^(p), —O—X⁴—CO₂R^(n), —O—X⁴—CONR^(n)R^(p), —X⁴—OR^(n),     —X⁴—NR^(n)R^(p), —X⁴—CO₂R^(n), —X⁴—CONR^(n)R^(p), —SF₅, and     —S(O)₂NR^(n)R^(p); -   wherein each X⁴ is a C₁₋₆ alkylene; each R^(n) and R^(p) is     independently selected from hydrogen, C₁₋₈ alkyl, and C₁₋₈     haloalkyl, or when attached to the same nitrogen atom can be     combined with the nitrogen atom to form a five or six-membered ring     having from 0 to 2 additional heteroatoms as ring members selected     from N, O or S, and optionally substituted with oxo; each R^(m) is     independently selected from the group consisting of C₁₋₈ alkyl, C₂₋₈     alkenyl, and C₁₋₈ haloalkyl; and optionally when two R^(4a)     substituents are on adjacent atoms, they are combined to form a     fused five or six-membered carbocyclic or heterocyclic ring     optionally substituted with oxo; -   the subscript n is 0, 1, 2 or 3; -   each R⁵ is independently selected from the group consisting of     halogen, —CN, —R^(q), —CO₂R^(r), —CONR^(r)R^(s), —C(O)R^(r),     —OC(O)NR^(r)R^(s), —NR^(r)C(O)R^(s), —NR^(r)C(O)₂R^(q),     —NR^(r)—C(O)NR^(r)R^(s), —NR^(r)R^(s), —OR^(r), —O—X⁵—OR^(r),     —O—X⁵—NR^(r)R^(s), —O—X⁵—CO₂R^(r), —O—X⁵—CONR^(r)R^(s), —X⁵—OR^(r),     —X^(S)—NR^(r)R^(s), —X⁵—CO₂R^(r), —X⁵—CONR^(r)R^(s), —SF₅,     —S(O)₂NR^(r)R^(s), wherein each X⁵ is a C₁₋₄ alkylene; each R^(r)     and R^(s) is independently selected from hydrogen, C₁₋₈ alkyl, and     C₁₋₈ haloalkyl, or when attached to the same nitrogen atom can be     combined with the nitrogen atom to form a five or six-membered ring     having from 0 to 2 additional heteroatoms as ring members selected     from N, O or S, and optionally substituted with oxo; each R^(q) is     independently selected from the group consisting of C₁₋₈ alkyl, and     C₁₋₈ haloalkyl; -   R^(6a) is selected from the group consisting of H, C₁₋₄ alkyl and     C₁₋₄haloalkyl; -   the subscript m is 0, 1, 2, 3 or 4; -   each R^(6b) is independently selected from the group consisting of     F, C₁₋₄ alkyl, O—R^(u), C₁₋₄ haloalkyl, NR^(u)R^(v), wherein each     R^(u) and R^(v) is independently selected from hydrogen, C₁₋₈ alkyl,     and C₁₋₈ haloalkyl, or when attached to the same nitrogen atom can     be combined with the nitrogen atom to form a five or six-membered     ring having from 0 to 2 additional heteroatoms as ring members     selected from N, O or S, and optionally substituted with oxo.

In some embodiments, the present disclosure provides compounds having the formula formula (Ia) or (Ib):

In some selected embodiments, the compounds of formula (I), (Ia) or (Ib) are those compounds wherein R¹ is selected from the group consisting of:

In some selected embodiments, the compounds of formula (I), (Ia) or (Ib) are those compounds wherein R¹ is selected from the group consisting of:

In some selected embodiments, the compounds of formula (I), (Ia) or (Ib) are those compounds wherein R¹ is:

In some embodiments, for each of formula (I), (Ia) and (Ib), or a pharmaceutically acceptable salt thereof, the group Z-L- is selected from the group consisting of:

In some embodiments, for each of formula (I), (Ia) and (Ib), or a pharmaceutically acceptable salt thereof, the group Z-L- is selected from the group consisting of:

In some embodiments, for each of formula (I), (Ia) and (Ib), or a pharmaceutically acceptable salt thereof, the group Z-L- is selected from the group consisting of:

In some embodiments, for each of formula (I), (Ia) and (Ib), and the further selected embodiments above, the compounds or a pharmaceutically acceptable salt thereof, are those wherein each of R^(2a), R^(2b) and R^(2c) is independently selected from the group consisting of hydrogen, halogen, CN, C₁₋₄ alkyl, and C₁₋₄ haloalkyl.

In some embodiments, for each of formula (I), (Ia) and (Ib), and the further selected embodiments above, the compounds or a pharmaceutically acceptable salt thereof, are those wherein R^(2b) and R^(2c) are both H and R^(2a) is selected from the group consisting of halogen, C₁₋₄ alkyl, C₂₋₄ alkenyl, C₁₋₃ haloalkyl, —CN, —OMe and OEt. In some embodiments, R^(2b) and R^(2c) are both H and R^(2a) is halogen. In some embodiments, R^(2b) and R^(2c) are both H and R^(2a) is Cl.

In some embodiments, for each of formula (I), (Ia) and (Ib), and the further selected embodiments above, the compounds or a pharmaceutically acceptable salt thereof, are those wherein R³ is NR^(g)R^(h). In some embodiments, R³ is selected from the group consisting of:

In some embodiments, for each of formula (I), (Ia) and (Ib), and the further selected embodiments above, the compounds or a pharmaceutically acceptable salt thereof, are those wherein R³ is NR^(g)R^(h). In some embodiments, R³ is selected from the group consisting of:

In some embodiments, for each of formula (I), (Ia) and (Ib), and the further selected embodiments above, the compounds or a pharmaceutically acceptable salt thereof, are those wherein R³ is NR^(g)R^(h). In some embodiments, R³ is selected from the group consisting of:

In some embodiments, for each of formula (I), (Ia) and (Ib), and the further selected embodiments above, the compounds or a pharmaceutically acceptable salt thereof, are those wherein R³ is —NR^(g)R^(h), and R^(h) combined with the N to which it is attached is a mono-, di- or tri-peptide comprising 1-3 natural amino acids and 0-2 non-natural amino acids, wherein the non-natural aminoacids have an alpha carbon substituent selected from the group consisting of C₂₋₄ hydroxyalkyl, C₁₋₃ alkyl-guanidinyl, and C₁₋₄ alkyl-heteroaryl, the alpha carbon of each natural or non-natural amino acids are optionally further substituted with a methyl group, and the terminal moiety of the mono-, di-, or tri-peptide is selected from the group consisting of C(O)OH, C(O)O—C₁₋₆ alkyl, and PO₃H₂.

In some embodiments, for each of formula (I), (Ia) and (Ib), and the further selected embodiments above, the compounds or a pharmaceutically acceptable salt thereof, are those wherein each natural amino acid of R^(h) is independently selected from the group consisting of serine, alanine, glycine, lysine, argining, threonine, phenylalanine, tyrosine, asparatate, asparagine, histidine, and leucine.

In some embodiments, for each of formula (I), (Ia) and (Ib), and the further selected embodiments above, the compounds or a pharmaceutically acceptable salt thereof, are those wherein R⁴ is selected from the group consisting of:

In some embodiments, for each of formula (I), (Ia) and (Ib), and the further selected embodiments above, the compounds or a pharmaceutically acceptable salt thereof, are those wherein R⁴ is selected from the group consisting of:

In some embodiments, for each of formula (I), (Ia) and (Ib), and the further selected embodiments above, the compounds or a pharmaceutically acceptable salt thereof, are those wherein R⁴ is:

In some embodiments, for each of formula (I), (Ia) and (Ib), and the further selected embodiments above, the compounds or a pharmaceutically acceptable salt thereof, are those wherein n is 0.

In some embodiments, for each of formula (I), (Ia) and (Ib), and the further selected embodiments above, the compounds or a pharmaceutically acceptable salt thereof, are those wherein R^(6a) and R^(6b) are each independently selected from the group consisting of hydrogen, halogen, C₁₋₄ alkyl and C₁₋₄ haloalkyl.

In some embodiments, for each of formula (I), (Ia) and (Ib), and the further selected embodiments above, the compounds or a pharmaceutically acceptable salt thereof, are those wherein

In addition to the compounds provided above, pharmaceutically acceptable salts of those compounds are also provided. In some embodiments, the pharmaceutically acceptable salts are selected from ammonium, calcium, magnesium, potassium, sodium, zinc, arginine, betaine, caffeine, choline, N,N′-dibenzylethylenediamine, diethylamine, 2-diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine, ethylenediamine, N-ethylmorpholine, N-ethylpiperidine, glucamine, glucosamine, histidine, hydrabamine, isopropylamine, lysine, methylglucamine, morpholine, piperazine, piperadine, procaine, purines, theobromine, triethylamine, trimethylamine, tripropylamine, tromethamine, hydrochloric, carbonic, monohydrogencarbonic, phosphoric, monohydrogenphosphoric, dihydrogenphosphoric, acetic, propionic, isobutyric, malonic, benzoic, succinic, suberic, fumaric, mandelic, phthalic, benzenesulfonic, p-tolylsulfonic, citric, tartaric, methanesulfonic, arginate, glucuronic acid and galactunoric acids. In some embodiments, the pharmaceutically acceptable salts are selected from ammonium, calcium, magnesium, potassium, sodium, hydrochloric, carbonic, monohydrogencarbonic, phosphoric, monohydrogenphosphoric, dihydrogenphosphoric, acetic, propionic, isobutyric, malonic, benzoic, succinic, suberic, fumaric, mandelic, phthalic, benzenesulfonic, p-tolylsulfonic, citric, tartaric, methanesulfonic, arginate, glucuronic acid and galactunoric acids. In some embodiments, the pharmaceutically acceptable salts are sodium or hydrochloric.

In addition to salt forms, the present disclosure provides compounds which are in a prodrug form. Prodrugs of the compounds described herein are those compounds that readily undergo chemical changes under physiological conditions to provide the compounds of the present disclosure. Additionally, prodrugs can be converted to the compounds of the present disclosure by chemical or biochemical methods in an ex vivo environment. For example, prodrugs can be slowly converted to the compounds of the present disclosure when placed in a transdermal patch reservoir with a suitable enzyme or chemical reagent.

An ester may be used as a prodrug for the corresponding carboxylic acid. A C₁₋₁₀ alkyl ester or a C₁₋₁₀ haloalkyl ester may be used as a prodrug for the corresponding carboxylic acid. The following esters may be used: ter-butyl ester, methyl ester, ethyl ester, isopropyl ester. More specifically, ester prodrugs may be used as R³ groups such as threonine or serine prodrug esters which are linked to the rest of the molecule through their nitrogen. More specifically, the following prodrugs may be used for R³:

More specifically, the following prodrugs may be used for R³:

Pharmaceutical Compositions

In addition to the compounds provided herein, compositions of those compounds will typically contain a pharmaceutical carrier or diluent.

The term “composition” as used herein is intended to encompass a product comprising the specified ingredients in the specified amounts, as well as any product which results, directly or indirectly, from combination of the specified ingredients in the specified amounts. By “pharmaceutically acceptable” it is meant the carrier, diluent or excipient must be compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.

In another embodiment, a pharmaceutical composition comprising a compound of the present disclosure including a compound of Formula (II), (IIa), (IIb), (I), (Ia), or (Ib) or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient, is provided.

In some embodiments, the pharmaceutical composition further comprises one or more additional therapeutic agents. In some embodiments, the one or more additional therapeutic agent is selected from the group consisting of an antimicrobial agent, an antiviral agent, a cytotoxic agent, a gene expression modulatory agent, a chemotherapeutic agent, an anti-cancer agent, an anti-angiogenic agent, an immunotherapeutic agent, an anti-hormonal agent, an anti-fibrotic agent, radiotherapy, a radiotherapeutic agent, an anti-neoplastic agent, and an anti-proliferation agent. In some embodiments, the one or more additional therapeutic agent is selected from the group consisting of one or more of CCX354, CCX9588, CCX140, CCX872, CCX598, CCX6239, CCX9664, CCX2553, CCX3587, CCX3624, CCX 2991, CCX282, CCX025, CCX507, CCX430, CCX765, CCX224, CCX662, CCX650, CCX832, CCX168, CCX168-M1, CCX3022 and CCX3384.

The pharmaceutical compositions for the administration of the compounds of this disclosure may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy and drug delivery. All methods include the step of bringing the active ingredient into association with the carrier which constitutes one or more accessory ingredients. In general, the pharmaceutical compositions are prepared by uniformly and intimately bringing the active ingredient into association with a liquid carrier or a finely divided solid carrier or both, and then, if necessary, shaping the product into the desired formulation. In the pharmaceutical composition the active object compound is included in an amount sufficient to produce the desired effect upon the process or condition of diseases.

The pharmaceutical compositions containing the active ingredient may be in a form suitable for oral use, for example, as tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsions and self-emulsifications as described in U.S. Patent Application 2002-0012680, hard or soft capsules, syrups, elixirs, solutions, buccal patch, oral gel, chewing gum, chewable tablets, effervescent powder and effervescent tablets. Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, flavoring agents, coloring agents, antioxidants and preserving agents in order to provide pharmaceutically elegant and palatable preparations. Tablets contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be for example, inert diluents, such as cellulose, silicon dioxide, aluminum oxide, calcium carbonate, sodium carbonate, glucose, mannitol, sorbitol, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example PVP, cellulose, PEG, starch, gelatin or acacia, and lubricating agents, for example magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated, enterically or otherwise, by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate may be employed. They may also be coated by the techniques described in the U.S. Pat. Nos. 4,256,108; 4,166,452; and U.S. Pat. No. 4,265,874 to form osmotic therapeutic tablets for control release.

Formulations for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, polyethylene glycol (PEG) of various average sizes (e.g., PEG400, PEG4000) and certain surfactants such as cremophor or solutol, or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example peanut oil, liquid paraffin, or olive oil. Additionally, emulsions can be prepared with a non-water miscible ingredient such as oils and stabilized with surfactants such as mono- or di-glycerides, PEG esters and the like.

Aqueous suspensions contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, for example sodium carboxymethylcellulose, methylcellulose, hydroxy-propylmethylcellulose, sodium alginate, polyvinyl-pyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents may be a naturally-occurring phosphatide, for example lecithin, or condensation products of an alkylene oxide with fatty acids, for example polyoxy-ethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, for example polyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives, for example ethyl, or n-propyl, p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents, such as sucrose or saccharin.

Oily suspensions may be formulated by suspending the active ingredient in a vegetable oil, for example arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as those set forth above, and flavoring agents may be added to provide a palatable oral preparation. These compositions may be preserved by the addition of an anti-oxidant such as ascorbic acid.

Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example sweetening, flavoring and coloring agents, may also be present.

The pharmaceutical compositions of the disclosure may also be in the form of oil-in-water emulsions. The oily phase may be a vegetable oil, for example olive oil or arachis oil, or a mineral oil, for example liquid paraffin or mixtures of these. Suitable emulsifying agents may be naturally-occurring gums, for example gum acacia or gum tragacanth, naturally-occurring phosphatides, for example soy bean, lecithin, and esters or partial esters derived from fatty acids and hexitol anhydrides, for example sorbitan monooleate, and condensation products of the said partial esters with ethylene oxide, for example polyoxyethylene sorbitan monooleate. The emulsions may also contain sweetening and flavoring agents.

Syrups and elixirs may be formulated with sweetening agents, for example glycerol, propylene glycol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative and flavoring and coloring agents. Oral solutions can be prepared in combination with, for example, cyclodextrin, PEG and surfactants.

The pharmaceutical compositions may be in the form of a sterile injectable aqueous or oleagenous suspension. This suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example as a solution in 1,3-butane diol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables.

The compounds of the present disclosure may also be administered in the form of suppositories for rectal administration of the drug. These compositions can be prepared by mixing the drug with a suitable non-irritating excipient which is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Such materials include cocoa butter and polyethylene glycols. Additionally, the compounds can be administered via ocular delivery by means of solutions or ointments. Still further, transdermal delivery of the subject compounds can be accomplished by means of iontophoretic patches and the like. For topical use, creams, ointments, jellies, solutions or suspensions, etc., containing the compounds of the present disclosure are employed. As used herein, topical application is also meant to include the use of mouth washes and gargles.

The compounds of this disclosure may also be coupled a carrier that is a suitable polymers as targetable drug carriers. Such polymers can include polyvinylpyrrolidone, pyran copolymer, polyhydroxy-propyl-methacrylamide-phenol, polyhydroxyethyl-aspartamide-phenol, or polyethyleneoxide-polylysine substituted with palmitoyl residues. Furthermore, the compounds of the disclosure may be coupled to a carrier that is a class of biodegradable polymers useful in achieving controlled release of a drug, for example polylactic acid, polyglycolic acid, copolymers of polylactic and polyglycolic acid, polyepsilon caprolactone, polyhydroxy butyric acid, polyorthoesters, polyacetals, polydihydropyrans, polycyanoacrylates and cross linked or amphipathic block copolymers of hydrogels. Polymers and semipermeable polymer matrices may be formed into shaped articles, such as valves, stents, tubing, prostheses and the like. In one embodiment of the disclosure, the compound of the disclosure is coupled to a polymer or semipermeable polymer matrix that is formed as a stent or stent-graft device.

Methods of Treating Diseases and Disorders

The compounds of the disclosure may be used as immunomodulators. The compounds of the disclosure may be used as agonists, antagonists, partial agonists, inverse agonists, inhibitors of PD-1 and/or PD-L1 in a variety of contexts, both in vitro and in vivo. In some embodiments, the compounds of the disclosure may be used as inhibitors of the PD-1/PD-L1 protein interaction. In some embodiments, the compounds of the disclosure may be used as inhibitors of PD-L1. In some embodiments, the compounds of the disclosure may be used as inhibitors of the CD80/PD-L1 protein interaction. In some embodiments, the compounds of the disclosure may be used to inhibit the interaction between PD-1 and PD-L1 and/or PD-1 and CD80 and/or PD-1 and PD-L2 in vitro or in vivo. In some embodiments, the compounds of the disclosure may be used to inhibit VISTA and/or TIM-3. In some embodiments, the compounds of the disclosure may be inhibitors of the PD-1/PD-L1 protein interaction and inhibitors of VISTA and/or TIM-3. In some embodiments, in addition to being inhibitors of the PD-1/PD-L1 protein interaction, the compounds of the disclosure may be inhibitors of CTLA-4 and/or BTLA and/or LAG-3 and/or KLRG-1 and/or 2B4 and/or CD160 and/or HVEM and/or CD48 and/or E-cadherin and/or MHC-II and/or galectin-9 and/or CD86 and/or PD-L2 and/or VISTA and/or TIM-3 and/or CD80.

The compounds of the disclosure may be contacted with the receptor they interact with, in aqueous solution and under conditions otherwise suitable for binding of the ligand to the receptor. The receptor may be present in suspension (e.g., in an isolated membrane or cell preparation), in a cultured or isolated cell, or in a tissue or organ.

Preferably, the amount of the compounds of the disclosure contacted with the receptor should be sufficient to inhibit the PD-1/PD-L1 binding in vitro as measured, for example, using an ELISA. The receptor may be present in solution or suspension, in a cultured or isolated cell preparation or within a patient.

In some embodiments, the compounds of the present disclosure are useful for restoring and augmenting T cell activation. In some embodiments, the compounds of the present disclosure are useful for enhancing an immune response in a patient. In some embodiments, the compounds of the present disclosure are useful for treating, preventing, or slowing the progression of diseases or disorders in a variety of therapeutic areas, such as cancer and infectious diseases.

In some embodiments, the compounds of the present disclosure can be used for treating patients suffering from conditions that are responsive to PD-1/PD-L1 protein interaction modulation.

In some embodiments, a method of modulating an immune response mediated by the PD-1 signaling pathway in a subject, comprising administering to the subject a therapeutically effective amount of a compound of the present disclosure including a compound of Formula (I), (Ia), (Ib), (II), (IIa), or (IIb), or a pharmaceutically acceptable salt thereof or a composition comprising a compound of Formula (I), (Ia), (Ib), (II), (IIa), or (IIb), or a pharmaceutically acceptable salt thereof, is provided.

In some embodiments, a method of enhancing, stimulating, modulating and/or increasing the immune response in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound of the present disclosure including a compound of Formula (I), (Ia), (Ib), (II), (IIa), or (IIb), or a pharmaceutically acceptable salt thereof or a composition of a compound of the present disclosure including a compound of Formula (I), (Ia), (Ib), (II), (IIa), or (IIb), or a pharmaceutically acceptable salt thereof, is provided.

In some embodiments, a method of inhibiting growth, proliferation, or metastasis of cancer cells in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound of the present disclosure including a compound of Formula (I), (Ia), (Ib), (II), (IIa), or (IIb), or a pharmaceutically acceptable salt thereof or a composition of a compound of the present disclosure including a compound of Formula (I), (Ia), (Ib), (II), (IIa), or (IIb), or a pharmaceutically acceptable salt thereof, is provided.

In some embodiments, a method of treating a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound of the present disclosure including a compound of Formula (I), (Ia), (Ib), (II), (IIa), or (IIb), or a pharmaceutically acceptable salt thereof or a composition of a compound of the present disclosure including a compound of Formula (I), (Ia), (Ib), (II), (IIa), or (IIb), or a pharmaceutically acceptable salt thereof, is provided.

In some embodiments, the subject suffers from a disease or disorder selected from the group consisting of an infectious disease, a bacterial infectious disease, a viral infectious disease a fungal infectious disease, a solid tumor, a hematological malignancy, an immune disorder, an inflammatory disease, and cancer. In some embodiments, the disease or disorder is selected from the group consisting of melanoma, glioblastoma, esophagus tumor, nasopharyngeal carcinoma, uveal melanoma, lymphoma, lymphocytic lymphoma, primary CNS lymphoma, T-cell lymphoma, diffuse large B-cell lymphoma, primary mediastinal large B-cell lymphoma, prostate cancer, castration-resistant prostate cancer, chronic myelocytic leukemia, Kaposi's sarcoma fibrosarcoma, liposarcoma, chondrosarcoma, osteogenic sarcoma, angiosarcoma, lymphangiosarcoma, synovioma, meningioma, leiomyosarcoma, rhabdomyosarcoma, sarcoma of soft tissue, sarcoma, sepsis, biliary tumor, basal cell carcinoma, thymus neoplasm, cancer of the thyroid gland, cancer of the parathyroid gland, uterine cancer, cancer of the adrenal gland, liver infection, Merkel cell carcinoma, nerve tumor, follicle center lymphoma, colon cancer, Hodgkin's disease, non-Hodgkin's lymphoma, leukemia, chronic or acute leukemias including acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, chronic lymphocytic leukemia, multiple myeloma, ovary tumor, myelodysplastic syndrome, cutaneous or intraocular malignant melanoma, renal cell carcinoma, small-cell lung cancer, lung cancer, mesothelioma, breast cancer, squamous non-small cell lung cancer (SCLC), non-squamous NSCLC, colorectal cancer, ovarian cancer, gastric cancer, hepatocellular carcinoma, pancreatic carcinoma, pancreatic cancer, Pancreatic ductal adenocarcinoma, squamous cell carcinoma of the head and neck, cancer of the head or neck, gastrointestinal tract, stomach cancer, HIV, Hepatitis A, Hepatitis B, Hepatitis C, hepatitis D, herpes viruses, papillomaviruses, influenza, bone cancer, skin cancer, rectal cancer, cancer of the anal region, testicular cancer, carcinoma of the fallopian tubes, carcinoma of the endometrium, carcinoma of the cervix, carcinoma of the vagina, carcinoma of the vulva, cancer of the esophagus, cancer of the small intestine, cancer of the endocrine system, cancer of the urethra, cancer of the penis, cancer of the bladder, cancer of the kidney, cancer of the ureter, carcinoma of the renal pelvis, neoplasm of the central nervous system (CNS), tumor angiogenesis, spinal axis tumor, brain stem glioma, pituitary adenoma, epidermoid cancer, asbestosis, carcinoma, adenocarcinoma, papillary carcinoma, cystadenocarcinoma, bronchogenic carcinoma, renal cell carcinoma, transitional cell carcinoma, choriocarcinoma, seminoma, embryonal carcinoma, wilm's tumor, pleomorphic adenoma, liver cell papilloma, renal tubular adenoma, cystadenoma, papilloma, adenoma, leiomyoma, rhabdomyoma, hemangioma, lymphangioma, osteoma, chondroma, lipoma and fibroma.

In some embodiments, a therapeutically effective amount of one or more additional therapeutic agents is further administered to the subject. In some embodiments, the one or more additional therapeutic agents is selected from the group consisting of an antimicrobial agent, an antiviral agent, a cytotoxic agent, a gene expression modulatory agent, a chemotherapeutic agent, an anti-cancer agent, an anti-angiogenic agent, an immunotherapeutic agent, an anti-hormonal agent, an anti-fibrotic agent, radiotherapy, a radiotherapeutic agent, an anti-neoplastic agent, and an anti-proliferation agent. In some embodiments, the one or more additional therapeutic agent is selected from the group consisting of one or more of CCX354, CCX9588, CCX140, CCX872, CCX598, CCX6239, CCX9664, CCX2553, CCX 2991, CCX282, CCX025, CCX507, CCX430, CCX765, CCX224, CCX662, CCX650, CCX832, CCX168, and CCX168-M1.

In some embodiments, the compounds of the present disclosure may be used to inhibit an infectious disease. The infectious disease includes but is not limited to HIV, Influenza, Herpes, Giardia, Malaria, Leishmania, the pathogenic infection by the virus Hepatitis (A, B, and C), herpes virus (e.g., VZV, HSV-I, HAV-6, HSV-II, and CMV, Epstein Barr virus), adenovirus, influenza virus, flaviviruses, echovirus, rhinovirus, coxsackie virus, coronavirus, respiratory syncytial virus, mumps virus, rotavirus, measles virus, rubella virus, parvovirus, vaccinia virus, HTLV virus, dengue virus, papillomavirus, molluscum virus, poliovirus, rabies virus, JC virus and arboviral encephalitis virus, pathogenic infection by the bacteria chlamydia, rickettsial bacteria, mycobacteria, staphylococci, streptococci, pneumonococci, meningococci and conococci, klebsiella, proteus, serratia, pseudomonas, E. coli, legionella, diphtheria, salmonella, bacilli, cholera, tetanus, botulism, anthrax, plague, leptospirosis, and Lyme's disease bacteria, pathogenic infection by the fungi Candida (albicans, krusei, glabrata, tropicalis, etc.), Cryptococcus neoformans, Aspergillus (fumigatus, niger, etc.), Genus Mucorales (mucor, absidia, rhizophus), Sporothrix schenkii, Blastomyces dermatitidis, Paracoccidioides brasiliensis, Coccidioides immitis and Histoplasma capsulatum, and pathogenic infection by the parasites Entamoeba histolytica, Balantidium coli, Naegleria fowleri, Acanthamoeba sp., Giardia lambia, Cryptosporidium sp., Pneumocystis carinii, Plasmodium vivax, Babesia microti, Trypanosoma brucei, Trypanosoma cruzi, Leishmania donovani, Toxoplasma gondi, Nippostrongylus brasiliensis.

In some embodiments, the compounds of the present disclosure may be used to inhibit HIV infection, delay AIDS progression, deplete HIV viral reservoir or decrease the severity of symptoms or HIV infection and AIDS.

The compounds of the present disclosure may be used for the treatment of cancers and precancerous conditions in a subject.

Treatment methods provided herein include, in general, administration to a patient an effective amount of one or more compounds provided herein. Suitable patients include those patients suffering from or susceptible to (i.e., prophylactic treatment) a disorder or disease identified herein. Typical patients for treatment as described herein include mammals, particularly primates, especially humans. Other suitable patients include domesticated companion animals such as a dog, cat, horse, and the like, or a livestock animal such as cattle, pig, sheep and the like.

In general, treatment methods provided herein comprise administering to a patient an effective amount of a compound one or more compounds provided herein. In a preferred embodiment, the compound(s) of the disclosure are preferably administered to a patient (e.g., a human) intravenously, orally or topically. The effective amount may be an amount sufficient to modulate the PD-1/PD-L1 interaction and/or an amount sufficient to reduce or alleviate the symptoms presented by the patient. Preferably, the amount administered is sufficient to yield a plasma concentration of the compound (or its active metabolite, if the compound is a pro-drug) high enough to sufficient to modulate the PD-1/PD-L1 interaction. Treatment regimens may vary depending on the compound used and the particular condition to be treated; for treatment of most disorders, a frequency of administration of 4 times daily or less is preferred. In general, a dosage regimen of 2 times daily is more preferred, with once a day dosing particularly preferred. It will be understood, however, that the specific dose level and treatment regimen for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, rate of excretion, drug combination (i.e., other drugs being administered to the patient) and the severity of the particular disease undergoing therapy, as well as the judgment of the prescribing medical practitioner. In general, the use of the minimum dose sufficient to provide effective therapy is preferred. Patients may generally be monitored for therapeutic effectiveness using medical or veterinary criteria suitable for the condition being treated or prevented.

Combinations

A concomitant medicine comprising the compounds of the present disclosure and other drug may be administered as a combination preparation in which both components are contained in a single formulation, or administered as separate formulations. The administration by separate formulations includes simultaneous administration and administration with some time intervals. In the case of the administration with some time intervals, the compound of the present disclosure can be administered first, followed by another drug or another drug can be administered first, followed by the compound of the present disclosure. The administration method of the respective drugs may be the same or different.

The dosage of the other drug can be properly selected, based on a dosage that has been clinically used. The compounding ratio of the compound of the present disclosure and the other drug can be properly selected according to age and weight of a subject to be administered, administration method, administration time, disorder to be treated, symptom and combination thereof. For example, the other drug may be used in an amount of 0.01 to 100 parts by mass, based on 1 part by mass of the compound of the present disclosure. The other drug may be a combination of two or more kind of arbitrary drugs in a proper proportion.

The compounds described herein may be used or combined with one or more therapeutic agent such as an antimicrobial agent, an antiviral agent, a cytotoxic agent, a gene expression modulatory agent, a chemotherapeutic agent, an anti-cancer agent, an anti-angiogenic agent, an immunotherapeutic agent, an anti-hormonal agent, an anti-fibrotic agent, radiotherapy, a radiotherapeutic agent, an anti-neoplastic agent, and an anti-proliferation agent. These therapeutic agents may be in the forms of compounds, antibodies, polypeptides, or polynucleotides.

The compounds described herein may be used or combined with one or more of a therapeutic antibody, a bispecific antibody and “antibody-like” therapeutic protein (such as DARTs®, Duobodies®, Bites®, XmAbs®, TandAbs®, Fab derivatives), an antibody-drug conjugate (ADC), a virus, an oncolytic virus, gene modifiers or editors such as CRISPR (including CRISPR Cas9), zinc finger nucleases or synthetic nucleases (TALENs), a CAR (chimeric antigen receptor) T-cell immunotherapeutic agent, or any combination thereof.

Examples of chemotherapeutics include an alkylation agent, nitrosourea agent, antimetabolite, anticancer antibiotics, vegetable-origin alkaloid, topoisomerase inhibitor, hormone drug, hormone antagonist, aromatase inhibitor, P-glycoprotein inhibitor, platinum complex derivative, other immunotherapeutic drugs and other anticancer drugs.

The compounds described herein may be used or combined with a cancer treatment adjunct, such as a leucopenia (neutropenia) treatment drug, thrombocytopenia treatment drug, antiemetic and cancer pain intervention drug, concomitantly or in a mixture form.

The compounds described herein may be used or combined with a kinase inhibitor.

In one embodiment, the compounds of the present disclosure can be used with other immunomodulators and/or a potentiating agent concomitantly or in a mixture form. Examples of the immunomodulator include various cytokines, vaccines and adjuvants. Examples of these cytokines, vaccines and adjuvants that stimulates immune responses include but not limited to GM-CSF, M-CSF, G-CSF, interferon-a, beta, or gamma, IL-1, IL-2, IL-3, IL-12, Poly (I:C) and CPG. The potentiating agents include cyclophosphamide and analogs of cyclophosphamide, anti-TGF and imatinib (Gleevac), a mitosis inhibitor, such as paclitaxel, Sunitinib (Sutent) or other antiangiogenic agents, an aromatase inhibitor, such as letrozole, an A2a adenosine receptor (A2AR) antagonist, an angiogenesis inhibitor, anthracyclines, oxaliplatin, doxorubicin, TLR4 antagonists, and IL-18 antagonists.

In some embodiments, the compounds described herein may be used or combined with one or more modulator of CCR1, CCR2, CCR3, CCR4, CCR5, CCR6, CCR7, CCR8, CCR9, CCR10, CCR11, CXCR1, CXCR2, CXCR3, CXCR4, CXCR5, CXCR6, CXCR7, ChemR23, C5aR, C5a, and C5. In some embodiments, the modulator is an antagonist.

In some embodiments, the compounds described herein may be used or combined with one or more of CCX354, CCX9588, CCX140, CCX872, CCX598, CCX6239, CCX9664, CCX2553, CCX 2991, CCX282, CCX025, CCX507, CCX430, CCX765, CCX224, CCX662, CCX650, CCX832, CCX168, and CCX168-M1.

Dosage

Dosage levels of the order of from about 0.1 mg to about 140 mg per kilogram of body weight per day are useful in the treatment or preventions of conditions involving the PD-1/PD-L1 interaction (about 0.5 mg to about 7 g per human patient per day). The amount of active ingredient that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. Dosage unit forms will generally contain between from about 1 mg to about 500 mg of an active ingredient. For compounds administered orally, transdermally, intravenously, or subcutaneously, it is preferred that sufficient amount of the compound be administered to achieve a serum concentration of 5 ng (nanograms)/mL-10 μg (micrograms)/mL serum, more preferably sufficient compound to achieve a serum concentration of 20 ng-1 μg/ml serum should be administered, most preferably sufficient compound to achieve a serum concentration of 50 ng/ml-200 ng/ml serum should be administered. For direct injection into the synovium (for the treatment of arthritis) sufficient compounds should be administered to achieve a local concentration of approximately 1 micromolar.

Frequency of dosage may also vary depending on the compound used and the particular disease treated. However, for treatment of most disorders, a dosage regimen of 4 times daily, three times daily, or less is preferred, with a dosage regimen of once daily or 2 times daily being particularly preferred. It will be understood, however, that the specific dose level for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, and rate of excretion, drug combination (i.e., other drugs being administered to the patient), the severity of the particular disease undergoing therapy, and other factors, including the judgment of the prescribing medical practitioner.

In another aspect of the disclosure, the compounds of the disclosure can be used in a variety of non-pharmaceutical in vitro and in vivo application. The compounds of the disclosure may also be used as positive controls in assays for PD-1/PD-L1 interaction activity, i.e., as standards for determining the ability of a candidate agent to bind to PD-1 and/or PD-L1, or as radiotracers for positron emission tomography (PET) imaging or for single photon emission computerized tomography (SPECT).

Also within the scope of the present disclosure are kits comprising a compound of the present disclosure or pharmaceutically acceptable salts thereof and instructions for use. The kit can further contain at least one additional reagent. Kits typically include a label indicating the intended use of the contents of the kit. The term label includes any writing, or recorded material supplied on or with the kit, or which otherwise accompanies the kit.

EXAMPLES

The following Examples illustrate various methods of making compounds of this disclosure including compounds of Formula (I), (Ia), or (Ib). The following examples are offered to illustrate, but not to limit the claimed disclosure.

Reagents and solvents used below can be obtained from commercial sources such as Aldrich Chemical Co. (Milwaukee, Wis., USA). ¹H-NMR spectra were recorded on a Varian Mercury 400 MHz NMR spectrometer. Significant peaks are provided relative to TMS and are tabulated in the order: multiplicity (s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet) and number of protons. Mass spectrometry results are reported as the ratio of mass over charge. In the examples, a single m/z value is reported for the M+H (or, as noted, M−H) ion containing the most common atomic isotopes. Isotope patterns correspond to the expected formula in all cases. Electrospray ionization (ESI) mass spectrometry analysis was conducted on a Hewlett-Packard MSD electrospray mass spectrometer using the HP1100 HPLC for sample delivery. Normally the analyte was dissolved in methanol or CH₃CN at 0.1 mg/mL and 1 microliter was infused with the delivery solvent into the mass spectrometer, which scanned from 100 to 1000 Daltons. All compounds could be analyzed in the positive or negative ESI mode, using acetonitrile/water with 1% formic acid as the delivery solvent.

The following abbreviations are used in the Examples and throughout the description of the disclosure: TLC means Thin layer chromatography.

Compounds within the scope of this disclosure can be synthesized as described below, using a variety of reactions known to the skilled artisan. One skilled in the art will also recognize that alternative methods may be employed to synthesize the target compounds of this disclosure, and that the approaches described within the body of this document are not exhaustive, but do provide broadly applicable and practical routes to compounds of interest.

Certain molecules claimed in this patent can exist in different enantiomeric and diastereomeric forms and all such variants of these compounds are claimed unless a specific enantiomer is specified.

The detailed description of the experimental procedures used to synthesize key compounds in this text lead to molecules that are described by the physical data identifying them as well as by the structural depictions associated with them.

Those skilled in the art will also recognize that during standard work up procedures in organic chemistry, acids and bases are frequently used. Salts of the parent compounds are sometimes produced, if they possess the necessary intrinsic acidity or basicity, during the experimental procedures described within this patent.

Example 1: Synthesis of (2S)-2-[[5-chloro-2-ethoxy-4-[[4-(2-fluorophenyl)indan-1-yl]amino]phenyl]methylamino]-3-hydroxy-propanoic acid

Step a: To a solution of 4-bromoindan-1-ol (12 g, 54 mmol) in THF (100 mL) was added N-ethyl-N-(propan-2-yl))propan-2-amine (50 mL, 290 mmol) and the solution was cooled to 0° C. Methanesulfonyl chloride (5.0 mL, 65 mmol) was added dropwise, the cooling bath was removed, and the mixture was stirred for an additional 2 h. Meanwhile, a separate flask was charged with ethyl 4-amino-5-chloro-2-ethoxybenzoate hydrochloride (13 g, 46 mmol), cesium carbonate (18 g, 55 mmol), sodium iodide (8.0 g, 53 mmol), and DMF (100 mL). To this mixture was added the indanol preparation, and the resulting mixture was stirred at 70° C. for 2 h. After cooling, the reaction mixture was filtered through a plastic fritted funnel and the filter cake was washed with dichloromethane. Most of the solvent was removed under reduced pressure, with only 40 mL of DMF remaining. The remaining mixture was taken up in ethyl acetate (200 mL) and water (200 mL). The aqueous phase was discarded and the organic phase was washed with brine and adsorbed onto silica gel (60 g). The mixture was purified by flash chromatography (6-12% EtOAc in hexane) to obtain crude ethyl 4-[(4-bromoindan-1-yl)amino]-5-chloro-2-ethoxy-benzoate (960 mg). MS: (ES) m/z calculated for C₂₀H₂₂BrClNO₃ [M+H]⁺ 438.0, found 438.1.

Step b: In a 40 mL vial was combined crude ethyl 4-[(4-bromoindan-1-yl)amino]-5-chloro-2-ethoxy-benzoate (960 mg), 2-fluorophenylboronic acid (330 mg, 2.4 mmol), tetrakis(triphenylphosphine)palladium (100 mg, 0.087 mmol), 2 M potassium carbonate (2 mL, 4 mmol), and 1,2-dimethoxyethane (8 mL). The mixture was degassed with a stream of nitrogen and stirred in the sealed vial at 80° C. for 1 h, after which the mixture was directly adsorbed onto silica gel and purified by flash chromatography to obtain 510 mg of ethyl 5-chloro-2-ethoxy-4-[[4-(2-fluorophenyl)indan-1-yl]amino]benzoate. MS: (ES) m/z calculated for C₂₆H₂₅ClFNO₃ [M+H]⁺ 454.2, found 454.1.

Step c: In a 40 mL vial, ethyl 5-chloro-2-ethoxy-4-[[4-(2-fluorophenyl)indan-1-yl]amino]benzoate (260 mg, 0.57 mmol) was dissolved in THE (4 mL) and cooled to 0° C. To this solution was added 1.0 M lithium aluminum hydride in THE (1.0 mL, 1.0 mmol) and this mixture was stirred for 1 h, at which point sodium sulfate decahydrate (1.0 g, 3.1 mmol) was added. The mixture was stirred for 12 h, then purified by flash chromatography (0-20% EtOAc in hexane) to obtain [5-chloro-2-ethoxy-4-[[4-(2-fluorophenyl)indan-1-yl]amino]phenyl]methanol (57 mg, 24%). MS: (ES) m/z calculated for C₂₄H₂₃ClFNNaO₂ [M+Na]⁺ 434.1, found 434.1.

Step d: To a solution of [5-chloro-2-ethoxy-4-[[4-(2-fluorophenyl)indan-1-yl]amino]phenyl]methanol (57 mg, 0.14 mmol) in dichloromethane (4 mL) cooled to 0° C. was added N-ethyl-N-(propan-2-yl))propan-2-amine (0.10 mL, 0.57 mmol) and methanesulfonyl chloride (0.020 mL, 0.26 mmol). The ice bath was removed, and the mixture was stirred for 1 h, at which point the mixture was combined with L-serine methyl ester hydrochloride (213 mg, 1.4 mmol) and additional N-ethyl-N-(propan-2-yl))propan-2-amine (0.24 mL, 1.4 mmol) and heated at 50° C. for 1d. The crude reaction mixture was diluted with dichloromethane and washed with saturated sodium bicarbonate solution. The organic phase was adsorbed onto silica gel and purified by flash chromatography to obtain methyl (2S)-2-[[5-chloro-2-ethoxy-4-[[4-(2-fluorophenyl)indan-1-yl]amino]phenyl]methylamino]-3-hydroxy-propanoate (9 mg, 13%). MS: (ES) m/z calculated for C₂₈H₃₀ClFN₂NaO₄ [M+Na]⁺ 535.2, found 535.1.

Step e: Methyl (2S)-2-[[5-chloro-2-ethoxy-4-[[4-(2-fluorophenyl)indan-1-yl]amino]phenyl]methylamino]-3-hydroxy-propanoate (9 mg, 0.018 mmol) was dissolved in MeOH (1 mL) and THE (1 mL) and stirred with aqueous lithium hydroxide (1 mL) for 12 h. Solvent was removed under reduced pressure and the residue was taken up in methanol and acetic acid and purified by reverse phase preparative HPLC (CH₃CN—H₂O with 0.1% TFA) to obtain (2S)-2-[[5-chloro-2-ethoxy-4-[[4-(2-fluorophenyl)indan-1-yl]amino]phenyl]methylamino]-3-hydroxy-propanoic acid. The pure fractions were neutralized with sodium bicarbonate; acetonitrile was removed under reduced pressure, and the product was extracted with 2:1 CHCl₃-2-propanol, dried with sodium sulfate, filtered and concentrated. The residue was lyophilized from acetonitrile-water to obtain a dry powder of the free form. MS: (ES) m/z calculated for C₂₇H₂₈ClFN₂NaO₄ [M+Na]⁺ 521.2, found 521.1. ¹H NMR (400 MHz, Methanol-d) δ 7.47-7.15 (m, 9H), 6.47 (d, J=2.4 Hz 1H), 5.27 (t, J=7.6 Hz, 1H), 4.31-4.13 (m, 2H), 4.10-3.95 (m, 3H), 3.90-3.85 (m, 1H), 2.92-2.85 (m, 2H), 2.65-2.56 (m, 1H), 2.04-1.94 (m, 1H), 1.41 (t, J=6.8 Hz, 3H).

Example 2: (2S)-2-[[5-chloro-2-ethoxy-4-[[4-[3-[3-(4-fluoro-1-piperidyl)propoxy]-2-methyl-phenyl]indan-1-yl]amino]phenyl]methylamino]-3-hydroxy-propanoic acid

Step a: Methyl 4-[(4-bromoindan-1-yl)amino]-5-chloro-2-ethoxy-benzoate was prepared by a procedure similar to that used to prepare ethyl 4-[(4-bromoindan-1-yl)amino]-5-chloro-2-ethoxy-benzoate. To a 40 mL vial was added methyl 4-[(4-bromoindan-1-yl)amino]-5-chloro-2-ethoxy-benzoate (205 mg, 0.48 mmol), 2-[3-(3-chloropropoxy)-2-methyl-phenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (194 mg, 0.62 mmol), tetrakis(triphenylphosphine)palladium (95 mg, 0.082 mmol), 2 M potassium carbonate (0.75 mL, 1.5 mmol), and 1,2-dimethoxyethane (7 mL). The mixture was thoroughly degassed with nitrogen and stirred at 80° C. for 1d. The mixture was diluted with ethyl acetate, washed with water, and adsorbed onto silica gel. Purification by flash chromatography (EtOAc-hexane) yielded 175 mg methyl 5-chloro-4-[[4-[3-(3-chloropropoxy)-2-methyl-phenyl]indan-1-yl]amino]-2-ethoxy-benzoate (69%).

Step b: To a 40 mL vial containing methyl 5-chloro-4-[[4-[3-(3-chloropropoxy)-2-methyl-phenyl]indan-1-yl]amino]-2-ethoxy-benzoate (175 mg, 0.33 mmol) dissolved in DMF (2 mL) was added 4-fluoropiperidine hydrochloride (135 mg, 0.96 mmol), sodium iodide (36 mg, 0.24 mmol), and potassium carbonate (340 mg, 2.5 mmol). The mixture was sonicated briefly, then stirred with heating at 70° C. for 2 h, then 80° C. for 2 h. The mixture was taken up with 2:1 chloroform-2-propanol and water, and the organic phase was separated and adsorbed onto silica gel. Purification by flash chromatography (2-20% methanol in dichloromethane) provided methyl 5-chloro-2-ethoxy-4-[[4-[3-[3-(4-fluoro-1-piperidyl)propoxy]-2-methyl-phenyl]indan-1-yl]amino]benzoate in quantitative yield, which was carried on to the next step without characterization. The residue was dissolved in THE (2 mL) and added to a suspension of lithium aluminum hydride (50 mg, 1.3 mmol) suspended in THE (2 mL) that had been cooled to 0° C. Afterwards, the ice bath was removed and the slurry was stirred at room temperature for 1 h and 45° C. for 30 m. The reaction was quenched by careful addition of a minimal amount of water and magnesium sulfate and purified by flash chromatography (4-100% acetone in hexane) to obtain [5-chloro-2-ethoxy-4-[[4-[3-[3-(4-fluoro-1-piperidyl)propoxy]-2-methyl-phenyl]indan-1-yl]amino]phenyl]methanol (51 mg, 27%, 2 steps). MS: (ES) m/z calculated for C₃₃H₄₁ClFN₂O₃ [M+H]⁺ 567.3, found 567.5.

Step c: To a solution of obtain [5-chloro-2-ethoxy-4-[[4-[3-[3-(4-fluoro-1-piperidyl)propoxy]-2-methyl-phenyl]indan-1-yl]amino]phenyl]methanol (51 mg, 0.090 mmol) in THF (2 mL) and cooled to 0° C. was added N-ethyl-N-(propan-2-yl))propan-2-amine (0.10 mL, 0.57 mmol) and methanesulfonyl chloride (0.040 mL, 0.52 mmol). The ice bath was removed and the mixture was stirred at room temperature. After 90 m, this mixture was added to a solution of L-serinie methyl ester hydrochloride (150 mg, 0.96 mmol) and N-ethyl-N-(propan-2-yl))propan-2-amine (0.17 mL, 0.98 mmol) in DMF (2 mL) and stirred at 70° C. for 16 h. The mixture was taken up in 2:1 chloroform-2-propanol and water, and the organic phase was separated, adsorbed onto silica gel, and purified by flash chromatography (2-80% ethanol in toluene) to obtain methyl (2S)-2-[[5-chloro-2-ethoxy-4-[[4-[3-[3-(4-fluoro-1-piperidyl)propoxy]-2-methyl-phenyl]indan-1-yl]amino]phenyl]methylamino]-3-hydroxy-propanoate. MS: (ES) m z calculated for C₃₇H₄₇ClFN₃NaO₅ [M+Na]⁺ 690.3, found 690.5.

Step d: To an 8 mL vial containing a solution of methyl (2S)-2-[[5-chloro-2-ethoxy-4-[[4-[3-[3-(4-fluoro-1-piperidyl)propoxy]-2-methyl-phenyl]indan-1-yl]amino]phenyl]methylamino]-3-hydroxy-propanoate dissolved in THF (0.60 mL) and methanol (0.60 mL) was added a solution of lithium hydroxide monohydrate (25 mg, 0.60 mmol) in water (0.60 mL). After stirring for 30 m, LCMS indicated hydrolysis of the ester was complete. The mixture was acidified with acetic acid and purified by reverse phase preparative HPLC (CH₃CN—H₂O with 0.1% TFA) to provide (2S)-2-[[5-chloro-2-ethoxy-4-[[4-[3-[3-(4-fluoro-1-piperidyl)propoxy]-2-methyl-phenyl]indan-1-yl]amino]phenyl]methylamino]-3-hydroxy-propanoic acid as the bis trifluoroacetate salt. MS: (ES) m/z calculated for C₃₆H₄₆ClFN₃O₅ [M+H]⁺ 654.3, found 654.3. ¹H NMR (400 MHz, Methanol-d) δ 7.33-7.25 (m, 3H), 7.20 (t, J=8.0 Hz, 1H), 7.06 (d, J=6.0 Hz, 1H), 6.95 (d, J=8.4 Hz, 1H), 6.76 (d, J=7.6 Hz, 1H), 6.53 (d, J=20 Hz, 1H), 5.31-5.19 (m, 1H), 5.00 (d, J=48 Hz, 1H), 4.29 (d, J=13 Hz, 1H), 4.21-4.13 (m, 3H), 4.13-3.96 (m, 4H), 3.91 (br s, 1H), 3.76-3.53 (m, 2H), 3.46-3.37 (m, 2H), 2.78-2.53 (m, 3H), 2.41-2.20 (m, 4H), 2.18-2.09 (m, 1H), 2.08-1.86 (m, 5H), 1.43 (t, J=6.8 Hz, 3H).

Compounds in Table 1 were prepared by methods as described in the Examples, and evaluated according to the assay below. The IC₅₀ of the compounds are presented in Table 1 as follows:

+, 20000 nM≥IC₅₀≥500 nM; ++, 500 nM>IC₅₀≥5 nM; +++, 5 nM>IC₅₀.

Characterization Conditions

Reverse phase HPLC conditions used for determination of retention times in Table 1:

Column: ZORBAX (SB-C18 2.1×50 mm, 5 μm)

Mobile phase A: 95% H₂O, 5% MeCN (with 0.1% Formic Acid)

Mobile phase B: 5% H₂O, 95% MeCN (with 0.1% Formic Acid)

Flow rate: 1.0 mL/min

Gradient: 20 to 100% B in 3.5 min

Biological Example: Enzyme-Linked Immunosorbent Assay—ELISA

Plates were coated with 1 μg/mL of human PD-L1 (obtained from R&D) in PBS overnight at 4° C. The wells were then blocked with 2% BSA in PBS (W/V) with 0.05% TWEEN-20 for 1 hour at 37° C. The plates were washed 3 times with PBS/0.05% TWEEN-20 and the samples were diluted to 1:5 in dilution medium in the ELISA plates. Human PD-1 and biotin 0.3 μg/mL (ACRO Biosystems) were added and incubated for 1 hour at 37° C. then washed 3 times with PBS/0.05% TWEEN-20. A second block was added with 2% SA in PBS (W/V)/0.05% TWEEN-20 for 10 min at 37° C. and was washed 3 times with PBS/0.05% TWEEN-20. Streptavidin-HRP was added for 1 hour at 37° C. then washed 3 times with PBS/0.05% TWEEN-20. TMB substrate was added and reacted for 20 min at 37° C. A stop solution (2 N aqueous H₂SO₄) was added. The absorbance was read at 450 nm using a micro-plate spectrophotometer. The results are shown in Table 1.

TABLE 1 ELISA RP- IC₅₀ MS HPLC Structure (nM) [M + H]⁺ R_(t) (min)

++ 663.3 1.87

+ 663.3 1.69

++ 677.2 1.78

+ 677.2 1.72

+ 684.2 2.51

+ 697.2 1.67

++ 652.2 1.99

++ 521.1 [M + Na] 2.88 

1. A compound of Formula (I):

or a pharmaceutically acceptable salt thereof, or a prodrug or bioisostere thereof, wherein: R¹ is Formula (IIb):

each of substitutents R^(1a), R^(1b), R^(1c) and R^(1d) is independently selected from the group consisting of H, halogen, —CN, —R^(c), —CO₂R^(a), —CONR^(a)R^(b), —C(O)R^(a), —OC(O)NR^(a)R^(b), —NR^(b)C(O)R^(a), —NR^(b)C(O)₂R^(c), —NR^(a)—C(O)NR^(a)R^(b), —NR^(a)R^(b), —OR^(a), —O—X¹—OR^(a), —O—X¹—CO₂R^(a), —O—X¹—CONR^(a)R^(b), —X¹—OR^(a), —X¹—NR^(a)R^(b), —X¹—CO₂R^(a), —X¹—CONR^(a)R^(b), —SF₅, and —S(O)₂NR^(a)R^(b), wherein each X¹ is a C₁₋₄ alkylene; each R^(a) and R^(b) is independently selected from hydrogen, C₁₋₈ alkyl, and C₁₋₈ haloalkyl, or when attached to the same nitrogen atom can be combined with the nitrogen atom to form a five or six-membered ring having from 0 to 2 additional heteroatoms as ring members selected from N, O or S, wherein the five or six-membered ring is optionally substituted with oxo; each R^(c) is independently selected from the group consisting of C₁₋₈ alkyl, C₂₋₈ alkenyl, C₂₋₈ alkynyl and C₁₋₈ haloalkyl; and optionally when two substituents are on adjacent carbon atoms of the benzene ring, they may combine to form a fused five, six or seven-membered carbocyclic or heterocyclic ring optionally substituted with from 1 to 3 substituents independently selected from halo, oxo, C₁₋₈ haloalkyl and C₁₋₈ alkyl; L is a linking group selected from the group consisting of:

wherein each of the subscripts q is independently 1, 2, 3 or 4, and L is optionally further substituted with one or two members selected from the group consisting of halogen, hydroxy, C₁₋₃ alkyl, —O—C₁₋₃ alkyl, C₁₋₃ hydroxyalkyl, C₁₋₃ haloalkyl and —CO₂H; Z is selected from the group consisting of azetidinyl, pyrollidinyl, piperidinyl, morpholinyl, pyridyl, pyrimidinyl, guanidinyl, quinuclidine, and 8-azabicyclo[3.2.1]octane, each of which is optionally substituted with from 1 to 3 groups independently selected from halogen, hydroxy, C₁₋₃ alkyl, —NH₂, —NHC₁₋₃alkyl, —N(C₁₋₃alkyl)₂, —O—C₁₋₃ alkyl, C₁₋₃ hydroxyalkyl, C₁₋₃ haloalkyl and —CO₂H; or Z is selected from the group consisting of —CO₂R^(z1) and —NR^(z1)R^(z2); wherein R^(z1) is selected from the group consisting of H, C₁₋₈ alkyl, C₁₋₈ haloalkyl and C₁₋₈ hydroxyalkyl; and R^(z2) is selected from —C₁₋₈ alkyl, C₁₋₈ haloalkyl, C₁₋₈ alkyl-COOH, C₁₋₈ alkyl-OH, C₁₋₈ alkyl-CONH₂, C₁₋₈ alkyl-SO₂NH₂, C₁₋₈ alkyl-PO₃H₂, C₁₋₈ alkyl-C(O)NHOH, —C(O)—C₁₋₈alkyl-OH, —C(O)—C₁₋₈ alkyl-COOH, C₃₋₁₀ cycloalkyl, —C₃₋₁₀ cycloalkyl-COOH, —C₃₋₁₀ cycloalkyl-OH, C₄₋₈ heterocyclyl, —C₄₋₈ heterocyclyl-COOH, —C₄₋₈ heterocyclyl-OH, —C₁₋₈ alkyl-C₄₋₈ heterocyclyl, —C₁₋₈ alkyl-C₃₋₁₀ cycloalkyl, C₅₋₁₀ heteroaryl and —C₁₋₈alkyl-C₅₋₁₀ heteroaryl; each R^(2a), R^(2b) and R^(2c) is independently selected from the group consisting of H, halogen, —CN, —R^(d), —CO₂R^(e), —CONR^(e)R^(f), —OC(O)NR^(e)R^(f), —NR^(f)C(O)R^(e), —NR^(f)C(O)₂R^(d), —NR^(e)—C(O)NR^(e)R^(f), —NR^(e)R^(f), —OR^(e), —X²—OR^(e), —X²—NR^(e)R^(f), —X²—CO₂R^(e), —SF₅, and —S(O)₂NR^(e)R^(f), wherein each X² is a C₁₋₄ alkylene; each R^(e) and R^(f) is independently selected from hydrogen, C₁₋₈ alkyl, and C₁₋₈ haloalkyl, or when attached to the same nitrogen atom can be combined with the nitrogen atom to form a five or six-membered ring having from 0 to 2 additional heteroatoms as ring members selected from N, O and S, and optionally substituted with oxo; each R^(d) is independently selected from the group consisting of C₁₋₈ alkyl, C₂₋₈ alkenyl, and C₁₋₈ haloalkyl; R³ is selected from the group consisting of —NR^(g)R^(h) and C₄₋₁₂ heterocyclyl, wherein the C₄₋₁₂ heterocyclyl is optionally substituted with 1 to 6 R^(3a); each R^(3a) is independently selected from the group consisting of halogen, —CN, —R^(i), —CO₂R^(j), —CONR^(j)R^(k), —CONHC₁₋₆ alkyl-OH, —C(O)R^(j), —OC(O)NR^(j)R^(k), —NR^(j)C(O)R^(k), —NR^(j)C(O)₂R^(k), —CONHOH, —PO₃H₂, —NR^(j)—X³—C(O)₂R^(k), —NR^(j)C(O)NR^(j)R^(k), —NR^(j)R^(k), —OR^(j), —S(O)₂NR^(j)R^(k), —O—X³—OR^(j), —O—X³—NR^(j)R^(k), —O—X³—CO₂R^(j), —O—X³—CONR^(j)R^(k), —X³—OR^(j), —X³—NR^(j)R^(k), —X³—CO₂R^(j), —X³—CONR^(j)R^(k), —X³—CONHSO₂R^(j) and SF_(s); wherein X³ is C₁₋₆ alkylene and is optionally further substituted with OH, SO₂NH₂, CONH₂, C(O)NHOH, PO₃H₂, COO—C₁₋₈alkyl or CO₂H, wherein each R^(j) and R^(k) is independently selected from hydrogen, C₁₋₈ alkyl optionally substituted with 1 to 2 substituents selected from OH, SO₂NH₂, CONH₂, C(O)NHOH, PO₃H₂, COO—C₁₋₈alkyl or CO₂H, and C₁₋₈ haloalkyl optionally substituted with 1 to 2 substituents selected from OH, SO₂NH₂, CONH₂, C(O)NHOH, PO₃H₂, COO—C₁₋₈alkyl or CO₂H, or when attached to the same nitrogen atom R^(j) and R^(k) can be combined with the nitrogen atom to form a five or six-membered ring having from 0 to 2 additional heteroatoms as ring members selected from N, O or S, and optionally substituted with oxo; each R^(i) is independently selected from the group consisting of —OH, C₁₋₈ alkyl, C₂₋₈ alkenyl, and C₁₋₈ haloalkyl each of which may be optionally substituted with OH, SO₂NH₂, CONH₂, C(O)NHOH, PO₃H₂, COO—C₁₋₈alkyl or CO₂H; R^(g) is selected from the group consisting of H, C₁₋₈ haloalkyl and C₁₋₈ alkyl; R^(h) is selected from —C₁₋₈ alkyl, C₁₋₈ haloalkyl, C₁₋₈ hydroxyalkyl, C₁₋₈alkyl-CO₂R^(j), C₁₋₈alkyl-CONR^(j)R^(k), and C₁₋₈ alkyl-CONHSO₂R^(j), C₁₋₈ alkyl-SO₂NR^(j)R^(k), C₁₋₈ alkyl-PO₃H₂, C₁₋₈ alkyl-C(O)NHOH, C₁₋₈ alkyl-NR^(h1)R^(h2), —C(O)R^(j), C₃₋₁₀ cycloalkyl, —C₃₋₁₀ cycloalkyl-COOR^(j), —C₃₋₁₀ cycloalkyl-OR^(j), C₄₋₈ heterocyclyl, —C₄₋₈ heterocyclyl-COOR^(j), —C₄₋₈ heterocyclyl-OR^(j), —C₁₋₈ alkyl-C₄₋₈ heterocyclyl, —C(═O)OC₁₋₈ alkyl-C₄₋₈ heterocyclyl, —C₁— alkyl-C₃₋₁₀ cycloalkyl, C₅₋₁₀ heteroaryl, —C₁₋₈ alkyl-C₅₋₁₀ heteroaryl, —C₁₋₈ alkyl-C₆₋₁₀ aryl, —C₁₋₈ alkyl-(C═O)—C₆₋₁₀ aryl, —CO₂—C₁₋₈ alkyl-O₂C—C₁₋₈ alkyl, —C₁₋₈ alkyl-NH(C═O)—C₂₋₈ alkenyl, —C₁₋₈ alkyl-NH(C═O)—C₁₋₈ alkyl, —C₁₋₈ alkyl-NH(C═O)—C₂₋₈ alkynyl, —C₁₋₈ alkyl-(C═O)—NH—C₁₋₈ alkyl-COOR^(j), and —C₁₋₈ alkyl-(C═O)—NH—C₁₋₈ alkyl-OR^(j) optionally substituted with CO₂H; or R^(h) combined with the N to which it is attached is a mono-, di- or tri-peptide comprising 1-3 natural amino acids and 0-2 non-natural amino acids, wherein the non-natural aminoacids have an alpha carbon substituent selected from the group consisting of C₂₋₄ hydroxyalkyl, C₁₋₃ alkyl-guanidinyl, and C₁₋₄ alkyl-heteroaryl, the alpha carbon of each natural or non-natural amino acids are optionally further substituted with a methyl group, and the terminal moiety of the mono-, di-, or tri-peptide is selected from the group consisting of C(O)OH, C(O)O—C₁₋₆ alkyl, and PO₃H₂, wherein R^(h1) and R^(h2) are each independently selected from the group consisting of H, C₁₋₆ alkyl, and C₁₋₄ hydroxyalkyl; the C₁₋₈ alkyl portions of R^(h) are optionally further substituted with from 1 to 3 substituents independently selected from OH, COOH, SO₂NH₂, CONH₂, C(O)NHOH, COO—C₁₋₈ alkyl, PO₃H₂ and C₅₋₆ heteroaryl optionally substituted with 1 to 2 C₁₋₃ alkyl substituents, the C₅₋₁₀ heteroaryl and the C₆₋₁₀ aryl portions of R^(h) are optionally substituted with 1 to 3 substituents independently selected from OH, B(OH)₂, COOH, SO₂NH₂, CONH₂, C(O)NHOH, PO₃H₂, COO—C₁₋₈alkyl, C₁₋₄alkyl, C₁₋₄alkyl-OH, C₁₋₄alkyl-SO₂NH₂, C₁₋₄alkyl CONH₂, C₁₋₄alkyl-C(O)NHOH, C₁₋₄alkyl-PO₃H₂, C₁₋₄alkyl-COOH and phenyl, and the C₄₋₈ heterocyclyl and C₃₋₁₀ cycloalkyl portions of R^(h) are optionally substituted with 1 to 4 R^(w) substituents; each R^(w) substituent is independently selected from C₁₋₄ alkyl, C₁₋₄ alkyl-OH, C₁₋₄ alkyl-COOH, C₁₋₄ alkyl-SO₂NH₂, C₁₋₄ alkyl CONH₂, C₁₋₄ alkyl-C(O)NHOH, C₁₋₄ alkyl-PO₃H, OH, COO—C₁₋₈ alkyl, COOH, SO₂NH₂, CONH₂, C(O)NHOH, PO₃H₂ and oxo; R⁴ is selected from the group consisting of O—C₁₋₈ alkyl, O—C₁₋₈ haloalkyl, C₆₋₁₀ aryl, C₅₋₁₀ heteroaryl, —O—C₁₋₄ alkyl-C₄₋₇ heterocycloalkyl, —O—C₁₋₄ alkyl-C₆₋₁₀aryl and —O—C₁₋₄ alkyl-C₅₋₁₀ heteroaryl, each of which is optionally substituted with 1 to 5 R^(4a); each R^(4a) is independently selected from the group consisting of halogen, —CN, —R^(m), —CO₂R^(n), —CONR^(n)R^(p), —C(O)R^(n), —OC(O)NR^(n)R^(p), —NR^(n)C(O)R^(p), —NR^(n)C(O)₂R^(m), —NR^(n)—C(O)NR^(n)R^(p), —NR^(n)R^(p), —OR^(n), —O—X⁴—OR^(n), —O—X⁴—NR^(n)R^(p), —O—X⁴—CO₂R^(n), —O—X⁴—CONR^(n)R^(p), —X⁴—OR^(n), —X⁴—NR^(n)R^(p), —X⁴—CO₂R^(n), —X⁴—CONR^(n)R^(p), —SF₅, —S(O)₂R^(n)R^(p), —S(O)₂NR^(n)R^(p), C₃₋₇ cycloalkyl and C₄₋₇ heterocycloalkyl, wherein the cycloalkyl and heterocycloalkyl rings are optionally substituted with 1 to 5 R^(t), wherein each R^(t) is independently selected from the group consisting of C₁₋₈ alkyl, C₁₋₈ haloalkyl, —CO₂R^(n), —CONR^(n)R^(p), —C(O)R^(n), —OC(O)NR^(n)R^(p), —NR^(n)C(O)R^(p), —NR^(n)C(O)₂R^(m), —NR^(n)—C(O)NR^(n)R^(p), —NR^(n)R^(p), —OR^(n), —O—X⁴—OR^(n), —O—X⁴—NR^(n)R^(p), —O—X⁴—CO₂R^(n), —O—X⁴—CONR^(n)R^(p), —X⁴—OR^(n), —X⁴—NR^(n)R^(p), —X⁴—CO₂R^(n), —X⁴—CONR^(n)R^(p), —SF₅, and —S(O)₂NR^(n)R^(p); wherein each X⁴ is a C₁₋₆ alkylene; each R^(n) and R^(p) is independently selected from hydrogen, C₁₋₈ alkyl, and C₁₋₈ haloalkyl, or when attached to the same nitrogen atom can be combined with the nitrogen atom to form a five or six-membered ring having from 0 to 2 additional heteroatoms as ring members selected from N, O or S, and optionally substituted with oxo; each R^(m) is independently selected from the group consisting of C₁₋₈ alkyl, C₂₋₈ alkenyl, and C₁₋₈ haloalkyl; and optionally when two R^(4a) substituents are on adjacent atoms, they are combined to form a fused five or six-membered carbocyclic or heterocyclic ring optionally substituted with oxo; the subscript n is 0, 1, 2 or 3; each R⁵ is independently selected from the group consisting of halogen, —CN, —R^(q), —CO₂R^(r), —CONR^(r)R^(s), —C(O)R^(r), —OC(O)NR^(r)R^(s), —NR^(r)C(O)R^(s), —NR^(r)C(O)₂R^(q), —NR^(r)—C(O)NR^(r)R^(s), —NR^(r)R^(s), —OR^(r), —O—X⁵—OR^(r), —O—X⁵—NR^(r)R^(s), —O—X⁵—CO₂R^(r), —O—X⁵—CONR^(r)R^(s), —X⁵—OR^(r), —X⁵—NR^(r)R^(s), —X⁵—CO₂R^(r), —X⁵—CONR^(r)R^(s), —SF₅, —S(O)₂NR^(r)R^(s), wherein each X⁵ is a C₁₋₄ alkylene; each R^(r) and R^(s) is independently selected from hydrogen, C₁₋₈ alkyl, and C₁₋₈ haloalkyl, or when attached to the same nitrogen atom can be combined with the nitrogen atom to form a five or six-membered ring having from 0 to 2 additional heteroatoms as ring members selected from N, O or S, and optionally substituted with oxo; each R^(q) is independently selected from the group consisting of C₁₋₈ alkyl, and C₁₋₈ haloalkyl; R^(6a) is selected from the group consisting of H, C₁₋₄ alkyl and C₁₋₄ haloalkyl; the subscript m is 0, 1, 2, 3 or 4; each R^(6b) is independently selected from the group consisting of F, C₁₋₄ alkyl, O—R^(u), C₁₋₄ haloalkyl, NR^(u)R^(v), wherein each R^(u) and R^(v) is independently selected from hydrogen, C₁₋₈ alkyl, and C₁₋₈ haloalkyl, or when attached to the same nitrogen atom can be combined with the nitrogen atom to form a five or six-membered ring having from 0 to 2 additional heteroatoms as ring members selected from N, O or S, and optionally substituted with oxo.
 2. The compound of claim 1, or a pharmaceutically acceptable salt thereof having the formula (Ia)


3. The compound of claim 1, or a pharmaceutically acceptable salt thereof having the formula (Ib)

4.-6. (canceled)
 7. The compound of claim 1, or a pharmaceutically acceptable salt thereof wherein the group Z-L- is selected from the group consisting of:


8. The compound of claim 1, or a pharmaceutically acceptable salt thereof wherein the group Z-L- is selected from the group consisting of:


9. The compound of claim 1, or a pharmaceutically acceptable salt thereof wherein the group Z-L- is selected from the group consisting of:


10. The compound of claim 1, or a pharmaceutically acceptable salt thereof wherein each of R^(2a), R^(2b) and R^(2c) is independently selected from the group consisting of hydrogen, halogen, CN, C₁₋₄ alkyl, and C₁₋₄ haloalkyl.
 11. The compound of claim 1, or a pharmaceutically acceptable salt thereof wherein R³ is —NR^(g)R^(h).
 12. The compound of claim 1, or a pharmaceutically acceptable salt thereof wherein R³ is selected from the group consisting of:


13. The compound of claim 1, or a pharmaceutically acceptable salt thereof wherein R³ is selected from the group consisting of:


14. The compound of claim 1, or a pharmaceutically acceptable salt thereof wherein R³ is selected from the group consisting of:


15. (canceled)
 16. The compound of claim 1, or a pharmaceutically acceptable salt thereof wherein R⁴ is selected from the group consisting of:


17. The compound of claim 1, or a pharmaceutically acceptable salt thereof wherein R⁴ is selected from the group consisting of:


18. The compound of claim 1, or a pharmaceutically acceptable salt thereof wherein n is
 0. 19. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein R^(6a) and R^(6b) are each independently selected from the group consisting of hydrogen, halogen, C₁₋₄ alkyl and C₁₋₄ haloalkyl.
 20. (canceled)
 21. A pharmaceutical composition comprising a compound of claim 1, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient. 22.-24. (canceled)
 25. A method of enhancing, stimulating, modulating and/or increasing the immune response in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound of claim 1, or a pharmaceutically acceptable salt thereof.
 26. A method of inhibiting growth, proliferation, or metastasis of cancer cells in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound of claim 1, or a pharmaceutically acceptable salt thereof.
 27. A method of treating a subject suffering from or susceptible to a disease or disorder mediated by the PD-1 signaling pathway, comprising administering to the subject a therapeutically effective amount of a compound of claim 1, or a pharmaceutically acceptable salt thereof.
 28. (canceled)
 29. The method of claim 27, wherein the disease or disorder is selected from the group consisting of melanoma, glioblastoma, esophagus tumor, nasopharyngeal carcinoma, uveal melanoma, lymphoma, lymphocytic lymphoma, primary CNS lymphoma, T-cell lymphoma, diffuse large B-cell lymphoma, primary mediastinal large B-cell lymphoma, prostate cancer, castration-resistant prostate cancer, chronic myelocytic leukemia, Kaposi's sarcoma fibrosarcoma, liposarcoma, chondrosarcoma, osteogenic sarcoma, angiosarcoma, lymphangiosarcoma, synovioma, meningioma, leiomyosarcoma, rhabdomyosarcoma, sarcoma of soft tissue, sarcoma, sepsis, biliary tumor, basal cell carcinoma, thymus neoplasm, cancer of the thyroid gland, cancer of the parathyroid gland, uterine cancer, cancer of the adrenal gland, liver infection, Merkel cell carcinoma, nerve tumor, follicle center lymphoma, colon cancer, Hodgkin's disease, non-Hodgkin's lymphoma, leukemia, chronic or acute leukemias including acute myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, chronic lymphocytic leukemia, multiple myeloma, ovary tumor, myelodysplastic syndrome, cutaneous or intraocular malignant melanoma, renal cell carcinoma, small-cell lung cancer, lung cancer, mesothelioma, breast cancer, squamous non-small cell lung cancer (SCLC), non-squamous NSCLC, colorectal cancer, ovarian cancer, gastric cancer, hepatocellular carcinoma, pancreatic carcinoma, pancreatic cancer, Pancreatic ductal adenocarcinoma, squamous cell carcinoma of the head and neck, cancer of the head or neck, gastrointestinal tract, stomach cancer, HIV, Hepatitis A, Hepatitis B, Hepatitis C, hepatitis D, herpes viruses, papillomaviruses, influenza, bone cancer, skin cancer, rectal cancer, cancer of the anal region, testicular cancer, carcinoma of the fallopian tubes, carcinoma of the endometrium, carcinoma of the cervix, carcinoma of the vagina, carcinoma of the vulva, cancer of the esophagus, cancer of the small intestine, cancer of the endocrine system, cancer of the urethra, cancer of the penis, cancer of the bladder, cancer of the kidney, cancer of the ureter, carcinoma of the renal pelvis, neoplasm of the central nervous system (CNS), tumor angiogenesis, spinal axis tumor, brain stem glioma, pituitary adenoma, epidermoid cancer, asbestosis, carcinoma, adenocarcinoma, papillary carcinoma, cystadenocarcinoma, bronchogenic carcinoma, renal cell carcinoma, transitional cell carcinoma, choriocarcinoma, seminoma, embryonal carcinoma, wilm's tumor, pleomorphic adenoma, liver cell papilloma, renal tubular adenoma, cystadenoma, papilloma, adenoma, leiomyoma, rhabdomyoma, hemangioma, lymphangioma, osteoma, chondroma, lipoma and fibroma. 30-31. (canceled) 